jump to navigation

The Wreck Diving Course, part II July 31, 2009

Posted by Chris Sullivan in Dive Log, Shipwrecks.
Tags: , , , , , , , , , , , , , , , , , ,
add a comment

The second phase of our wreck penetration training was on the Kinghorn, just off shore from the small town of Rockport which is a little bit upriver from Brockville. After the Gaskin, this wreck increases the difficulty level because its deeper (at 95 feet), more enclosed (although there are still plenty of openings in the deck, and gets even darker when silt is present (because of the depth, few opening for the light, and the darker silt due to the fire during the sinking).

I was fortunate that on the Gaskin dive I let Rich use my doubles with the 40 mix. That prevented a wasted fill ($28 in Brockville) as EAN40 is too rich for that depth, and we filled up with 36 at DiveTech (which turned out to be only EAN34 after we measured it), a fabulously well-equipped nearby dive shop. With only 4 students on the wreck we were able to get through it quickly even though each went through twice. To save time, we had all 4 students inside at once on the second dive, but even through there were multiple penetration lines on many of the uprights, even after the silt-out there was little in the way of conflict. My Shearwater Pursuit, set to conservative gradient factors, gave me a little bit of deco time on each of the two dives, which lasted about 40 minutes. Curiously, one of those schedules was only at 20 feet.

Rich decided to switch to a dry suit for these dives. The boat had to tie to the buoy at the bow rather than the stern this time, so we had to use a tag line to pull ourselves upriver to the buoy which was attached by a sturdy line wreck. I had gone first and didn’t find out until later that the extra drag of the dry suit in the moving water had tired him out and he wisely decided to call the dive.

Rory was my first student. I though he would tie at the entrance where I’d seen a convenient spot, but he decided to use the rail well away from the entry point. I descended through the large hatchway feet first so I could watch him enter, but he decided to enter the same way, which is not as clean as a head first entry. Dave was signaling to me furiously and I didn’t understand until we surfaced that he wanted me to be much more decisive in letting the students know where to tie the line and to do a head first penetration. Despite all this, they successfully ran from one end to the other and returned safely and with lots of air left.

On the second dive, Rich managed his energy better so all four of us arrived at the wreck together. I was now emphatically directing the students, and the penetration went well. Dave and I took two students with me leading and Dave in the back. I kept them apart from the other pair of students coming in the other direction and it all worked very well in spite of the crowd.

On the return leg of that dive, my job was to stir up as much silt as possible, but also to monitor the divers in the near zero visibility conditions. The silt in the Kinghorn is very heavy, and it some effort to create an almost total blackout. Fortunately I found an area where it was about 6 inches deep which made it easy to grab big handfuls and throw it around. By staying slightly above the students after that, I could see way more than they could, making for a perfect setup where I could keep track of them easily, see the exits clearly, while they couldn’t see a thing most of the time and had to rely on their penetration lines.

Back on the boat, there were big smiles all around from divers who were deservedly proud of successfully pushing their own limits.

Solo Dive at Big Bay Point July 25, 2009

Posted by Chris Sullivan in Dive Log.
Tags: , , , , , , ,
add a comment

I’ve done precious few night dives in my time, 3 to be exact, or just over 1% of my total dives. At this time of year in Canada sunset is around 9pm, at which time I’m usually thinking about retiring for the night, being a fairly early riser. Last Wednesday night was no exception. The dive club was meeting for an afternoon dive then a night dive, and rushing back from my job in downtown Toronto I managed to arrive just after 7pm, just in time to be too early for the night dive and too late for dive #1.

The conditions were excellent that evening. There was barely a ripple in the water and the air was warm. Half a dozen fishermen were on the dock, so I was careful not to be too near their lines when entering the water or swimming out to the float, which had already been set up by the other divers.

With all the other divers either already in the water or just on their way out, I had no buddy. I elected to dive solo, reasoning that for shallow dives  I was no worse off than when teaching uncertified students. So in the water at quarter to eight, I headed initially to my maximum depth of 53′, returning quickly to the two inboard/outboards lying together at 40′, where I saw a couple of large Carp. In my haste to pack my car the night before, I’d forgotten one of my gloves which had dropped behind my lawn tractor out of sight. Fortunately the water wasn’t too cold – 62F (17C) at the deepest point but much warmer for most of the dive so I wasn’t bothered by its absence.

After examining the Carp for a while, I followed the line from the postbox out to the speedboat, which lies at a depth of 30′ well east of the main line. There were several bass hanging around it, none caring that much about my presence. At this point I thought it might be nice to practice underwater searches, so I tied a line to a cleat on the topside bow of the boat, and commenced a pendulum search in a semi-circle running from directly east, to north, then west of the tie-off point.

With each swing of the pendulum, I let out more line from my reel – about 4 frog-kicks worth. This sculling kick is taught in the wreck course and soon becomes habit, as it is both a comfortable means of propulsion and avoids stirring the bottom, even when the diver is very close to it. While our wreck students claimed having difficulty mastering it, we pressed them at it to help them learn to swim through wrecks without wrecking the visibility.

There is not much to be found in that area of the lake. The only thing to be seen other than a few weeds and Zebra Mussels was a telephone pole mostly submerged directly north of the speedboat lying NNE to SSW I held my compass against the reel so that when it read South I would know to turn around. That was quite effective and I noticed that the Lake was slightly shallower (about 27′) at the Easterly extremity of the search pattern. Eventually, I decided that my air supply was at the point where I should return to the float, so I tied a knot in the line to mark my greatest distance from the speedboat. I measured it today at just over 80 feet.

Now the circumference of a circle can be found using the formula 2πr, so a semi-circle would just be πr, or for me about 251 feet. I counted 107 frog kicks on my maximum traverse, or about 2.35′ per kick. I will admit right now that this wasn’t very much, but I was kicking gently so as not to stir up the silt.

The area of a circle is the old familiar formula πr², so my semicircle is just half that, which means that I searched an area a smidgen over 10,000 square feet. This is exactly the requirement for the larger area search for the Search and Recovery Diver Specialty dive #1, so it’s a good one to bear in mind.

Once I’d recovered the line onto my reel and untied it from the cleat, I headed back to the post box and the security of the ascent line to the float and flag. I hung around there looking around for a while and was just hanging there practicing neutral buoyancy in a horizontal position. I noticed that with 10lbs of weight in my weight pockets and the single tank adapter on my OMS backplate and wings, that I tended toward the vertical position. In the same rig and a dry suit I tend toward horizontal when the doubles are mounted, but with no weight. I’ll have to find a way to move my weight forward. In the wet suit, the BC is slightly loose and I can pull it up a bit which makes the trim better but that’s not the best solution by a long shot.

My horizontal meditiations were suddenly disturbed when I caught a massive silt cloud looming in the corner of my eye. 3 divers had arrived, and one was vertical and kicking furiously, blowing up silt like an approaching thunderstorm kicks up dust in its wake. I waved, then deciding it was as good a time an any to ascend, made a slow free ascent next to the line with a 3 minute safety stop. With almost no current it was easy to just hang there and weight out the countdown on my computer.

As I left the water the sun was just setting, 10 minutes before official sunset. Another opportunity for a night dive gone. The water was still calm and the air still warm, so a had a pleasant slow swim back to the dock, so unlike the conditions I’ve often encountered where we’d be struggling in our gear against the wind, waves and current. The fisherman will still there after a dive of exactly 60 minutes, and I headed back to the car to unload everything in a head into the trunk to make a quick exit, made all the more urgent by an email from my wife stating she was on an earlier train.

I broke several provisions of the highway traffic act to get the train station in reasonable time, only leaving her waiting for about three minutes, and we both headed home for the night.

Wreck training on the Gaskin, ’09 July 20, 2009

Posted by Chris Sullivan in Dive Log, Shipwrecks, Technical Diving, Training.
Tags: , , , , , , , , , , , , , , , ,

The Gaskin is an old shipwreck sitting not far from the shore off Brockville at around 60-70 feet. It can be accessed as a shore dive if you bring lots of air, but I’ve always gone there from a boat. On this occasion I was going into the wrecks to lead the students through, with some help from Dave, an assistant instructor who’d been doing this for years. Just like in the movies where the green lieutenant goes into battle with the experienced sergeant, I followed all his advice.

Going down to the wrecks in the St. Lawrence is always impressive. The dive usually starts with a (hopefully) minor struggle to grab the line from the buoy to the wreck while fighting the current, then pulling yourself down hand over hand where the only thing in sight other than the turbid water is the line disappearing down into the haze. It’s best not to look behind you as the current can take your mask off when it gets strong. Eventually, the bottom, then the basket holding the line or the wreck itself appears from the gloom.

The Gaskin is around 130′ long and has an easy entrance from the stern and another in the port bow. We use these as entrances each taking one student through each, tying off their penetration lines on the outside and at various points within. Most of the good upright attachment points are along the centreline, so they had to manage keeping lines clear of each other on the same post. The reason it makes a good first wreck to practice penetration is that the deck is very broken up, so getting out isn’t much more difficult than going straight up.

Dave thought I was too laissez-faire with the direction. At this stage he wanted me to point to exactly where the student was going to attach the line, and indeed that worked much better. It’s confusing enough to be in that environment in the first place and learning a new skill, so removing the need to make that kind of decision not only makes for better practice but speeds things up a lot.

On Saturday, July 20, 2009, each student got to do the wreck twice, once from each end. The second time after I led the student out, Dave silted the inside of the wreck to reduce the visibility to zero in some spots and just really bad in others. I kept a couple of fingers on the divers’ shoulder while they reeled in the line so I would know they were OK but couldn’t really see them. I don’t think they realized that if you looked up, you could usually see the light from one of the many exits in the deck.

We had to remind everyone to remain horizontal throughout the penetration and to scull with their fins to avoid silting, but for the most part the lines were kept taut and the attachments were done properly. The instructors’ dives were all around 1 hour and 40 minutes, but with the 40% nitrox mix and by hanging out on the upper part of the wreck while we were waiting, we managed to last through the dive without required decompression.

Deco diving the Shearwater Pursuit July 19, 2009

Posted by Chris Sullivan in Equipment, Shipwrecks, Technical Diving, Training.
Tags: , , , , , , , , , , , , , , ,
add a comment

Did 3 dives yesterday to a couple of wrecks, one at 65 feet (the Gaskin) for an hour and forty minutes on EAN39, then two to 95 feet (the Kinghorn) each for almost 40 minutes on EAN 34, with only about 20 minutes of surface interval between dives 2 and 3.

The computer when into deco on both the 2nd and 3rd dives. On the 3rd, it was quite odd that the only required stop was at 20 feet, and then it cleared, with no stop needed at 10 feet. On the first dive I also had some EAN50 and I used it while waiting for students to arrive on the wreck. This helped keep the computer well out of deco.

Once again, compared to my fellow divers with Cochran computers, I had deco while they were far from it. They were using slightly richer mixes than I (or at least they measured them higher), but the Shearwater’s default setting of GF 30/85 seems much more conservative than the Cochrans. I’m doing a longer deeper dive tomorrow on the Daryaw, so I’ll see how much I rack up for that. I might set it to 10/90 as it will be my only dive of the day.

I also changed the backlighting mode on the computer to light up whenever I pressed a button. Because the display changes when you do this you have to cycle back to the  main display if that’s want you want to see, but I found it more satisfactory to be able to turn the light on and off when I needed it than to use the automatic mode. Also, in auto mode when you shine your light on the computer the backlight goes out, so if you want to have both to read it more easily you can do that.

I did some gas switches underwater today as well. These are so simple they’re not really worth describing. Just 3 button pushes for the standard switch to the highest percentage O2 gas.

Heading up to Brockville July 18, 2009

Posted by Chris Sullivan in Fitness and Nutrition, Shipwrecks, Technical Diving, Training.
Tags: , , , , , , , , , , , , , , , , ,
add a comment

Last night I went over to the dive shop to pick up my tanks. It was a little confused, with about a dozen divers filling and blending Nitrox for the wreck diving course in the St. Lawrence River. My tanks were filled and I took them away, although I left my new (bought used) Faber 45 tank which Ron said he’d bring up once it had been topped off with air. Dave also donated his extra set of OMS steel 85 doubles to the cause, which I’m going to use on the first dive, which is a little shallower than the other two.

I got a late start and caught in traffic on the way up today, and didn’t get there until 8 pm, having left at 4. Traffic was heavy gettting out of Toronto and didn’t clear up until I was past Oshawa. When I got there, I started checking the mix on my tanks, and found that my doubles were at 39.5%, and Dave’s were about the same. For the Gaskin, with a maximum depth of 70 feet this is fine, but a little rich for the Kinghorn which can go as deep as 95′.

Fortunately Rich, who’s only brough one set, had his at 36%, so I offered to let him use my doubles on the first dive, and he will refill mine with 36% tomorrow between the two dives. My two AL80s were also filled to 50%, which is a little more than I wanted, so now I have a ton of deco gas. We were supposed to bring 36% and 40% in these, so I hope some of the other guys have that or we’re going to have to be careful how we do things, especially on the deeper dive. My new 45 cubic foot tank is also at 50%, which is fine, although I would have preferred 80% to get me out of the water faster on the last dive, which is a little bit long.

We didn’t end up diving tonight – too bad, but it would have been too late for me anyway with the late start.

A Friend’s First Impressions of the VRx July 17, 2009

Posted by Chris Sullivan in Equipment.
Tags: , , , , , , , , , , , , , , , ,
add a comment

I received this email a few weeks ago from one of my diving buddies. He’s getting along with it a bit better now that he’s getting to know its quirks. In contrast, I knew everything about operating my Shearwater Pursuit before I got into the water. It hasn’t surprised me once. The variable response time I noticed when playing with it at a dive club meeting was the biggest turn-off for me personally, and he notes that in these comments. The Liquivision X1 appears to be a great computer as well, but at double the price of the Shearwater it’s a bit steep.

I thought I’d pass along my experience so far with my VRx.  The report is less than complete and less than uplifting.

It starts with the strap….

Apparently a good design the strap can be deceiving.  First, as you may have discovered, you have to remove those two screws in order to get the strap in place.  When I was at the St. Lawrence with Mari I tried to get the strap in without removing the screws.  I placed the VRx face down on the plastic bed liner in my SUV and futzed around with it for a while.  I was rewarded with micro-scratches on the surface of the VRx.  Whatever you do, DON’T LIE THE THING FACE DOWN.  Out of all my instruments this is the least durable.  I decided not to dive it that day as losing it in the river on its maiden voyage would suck.

I finally got the strap installed correctly a few days later.  What a major pain in the ass.  Here’s another thing I discovered;  The strap’s clip, which seems like a good idea, is a major pain in the ass when gearing up.  I have mine snug for my drysuit and you have to ask someone to hold one end for you lest you have to rest the fragile surface of the thing on something that might scratch it (ie: something not a gas, although I’ll bet gas could scratch it too).

As I’m sure you have, I’ve been farting around with the VRx and I believe I’ve got the profiles set up correctly.  I was going to Big Bay Point to DM for Len this past weekend.  I figured an Air profile would be good.  Nothing too complex.  One thing I did notice is that sometimes the thing slows down like a Windows machine that’s been running for a couple of weeks on end.  That scares me as the software is doing something bad.  Other times it’s very snappy though.  The menus are a bit arcane and I’ve found myself lost and/or confused several times.  That, however, can be fixed with training.

Ok, so now its on my left wrist in the pole position with the EMC-16 further up my left arm as backup.  Lenka (this new Divemaster Candidate) and I are off to set the flag.  SPLASH!  We start swimming out and a few feet down I see my Cochran in dive mode but not the VRx.  It seems to take longer (deeper) to decide the dive has begun.  Now for the problem;  I couldn’t read the freaking thing at all!  I don’t know if it was the color (more on that later) or the terribly small font on the tiny screen but I could barely make out the readings.  I could clearly read my Cochran and even the small hash marks on my compass.  Bear this in mind though;  I wear bifocals and my prescription should be updated.  I’ve been putting it off but plan to get re-tested.  At that point I’ll update my mask script too but even for now I can still use the EMC-16.

I don’t know how great an idea color actually is since wavelengths disappear with depth.  I guess if the “emitter” is close enough to your eye (say on your wrist for instance) you can still make it out.  I could clearly see the color red at 40 feet but I could barely make out the depth or dive time.  Good thing I didn’t have to go into deco.  The color issue, however, was resolved for me.  After the third dive the color feature turned off just like it said in the manual.  It’s only turned on for three dives as a teaser.

I did enter the PIN as instructed by the manual.  That was the biggest pain in the ass I’ve had in a while.  None of the advanced features turned on (eg: color, gas management, big fonts, games, etc…).  Brad said we got everything but the PDF reader.  That is odd as the PDF reader comes with the “Games” option.  The Gas Management comes bundled with Big Fonts.  I smell a [charlie foxtrot] coming on…

The Logbook feature of the VRx is pretty cool providing dive information (differing slightly in both times and depths from the EMC-16) and graphs of the dive.  It would be nice to be able to move backward through the logbook rather than only forward but the Cochran can’t do that either.  Overall the VRx has a sweet logbook function.  I’d like to see what it can do connected to a PC.

I’d like to give you a more complete (and more uplifting) report but being unable to read the display made diving the VRx a bit difficult.

What’s worse is I got to talk to one of that group of Tec divers that show up at BBP every now and again.  They had just done a long deco dive and we were talking about computers. They use the Liquivision X1.  The little thing is tiny with an easy to follow menu system (using English words rather than pictures) and I was able to read the OLED screen very clearly from several feet away (and up close) despite the unit’s tiny footprint.  It was pretty damn impressive!

I’m not put off by the VRx but I either have to get the big fonts going or my script replaced before I can actually use it.  I don’t ever want to find myself alone with a deco obligation and a computer showing me a schedule I can’t make out.

PS:  Let’s dive soon (I’m away this weekend though)
PPS:  Chris – stop saying “I told you so”

Wreck Diving Course: Laying Lines July 16, 2009

Posted by Chris Sullivan in Shipwrecks, Training.
Tags: , , , , , , , , , , , , , , ,
add a comment

CCDWD.Jason 1

CCDWD.Jason 2Last night the 4 remaining students on our wreck diving course breezed through the classroom work and then headed out across the street to the public park to practice with their reels. It was raining lightly and a little cool so noone really wanted to stay out there for very long, and consequently we had as many as 3 people laying lines at the same time in the same place.

This has been a July tradition with the dive shop for many years, and as time has passed the trees have grown to the point where even those of us with long arms have difficulty reaching around to wrap the lines. Fortunately there were willing helpers to assist in that aspect of the procedure, so the students could concentrate on the parts that were nearer to the real thing.

Each student has to lay a line from one tree to the next while keeping the line taut, and then reel it back in without snagging the reel or letting the line go slack. One accomplished, they do it again but reeling back is done with a blacked-out mask, simulating a complete silt-out inside the wreck. All of our students did a great job, despite having multiple lines with which to contend.

The actual diving takes place this weekend in the St. Lawrence River near Brockville. We’ll be diving three wrecks – the Robert Gaskin, the Kinghorn and the Henry C. Daryaw.

CCDWD.Kelly 1CCDWD.Kelly 2

With several dives happening on the same day, we’re going to use optimum mixes of Nitrox, and as the dives are also deep, the prerequisite for this course is both Advanced Open Water and Enriched Air Diver. This time we have 2 Advanced Open Water divers, a Divemaster in Training, and a Divemaster. They’re all looking forward to diving, as are the instructors and safety divers.


Next  stop, the Thousand Islands. We’re also trying to organize a dive of the Rothesay or Conestoga early Friday evening.

Luxfer Cylinders are back July 15, 2009

Posted by Chris Sullivan in Equipment.
Tags: , , , , , , , , , ,
add a comment

I didn’t know they were gone, but I found this article that said production had been stopped a few months ago , which I guess left Catalina the run of the market, since they’re the only two manufacturers of Aluminum cylinders to my knowledge. Glad they’re back at it though. It’s good to know that the Scuba biz is strong enough to support them.

Back to the Forest City July 14, 2009

Posted by Chris Sullivan in Dive Log, Shipwrecks, Technical Diving, Training.
Tags: , , , , , , , , , , , , , , , , ,
add a comment

London, Ontario, where I lived for 17 years, likes to call itself the Forest City, but there are several Forest Cities in the Great Lakes region so the ship could be named after any of them.

This time, on August 8, 2008, armed with my Tec Deep certification and full technical gear, I could “legally” venture below 130 feet.  Even so, this third expedition was my shallowest dive on the Forest City to date, as I with with some other guys doing simulated decompression only as they were still in training. I dutifully cut short my dive and “decompressed” for 15 minutes on EAN48, with only 1 minute of actual decompression time.

The water temperature at depth was a mere 6 degrees Celsius (43F) but I was warm enough in my dry suit. It was the happy time when both my Apeks Quantum computers were working so I was wearing both rather than relying on tables for deco. At around 130 feet deep I noticed that there was a hatch in the middle of the deck. I’m going to stick my head in that to see what’s in there next time I dive it, which will be in August, unless I am accompanying students, of course.

Total dive time was 46 minutes, and I burned my doubles from 2900 to 1500 PSI, and my AL80 deco from 2900 to 2100 PSI. I took some photos with the Nikonos but as I mentioned some time ago the film was destroyed while I was in Pensacola.

Further Adventures at Big Bay Point July 13, 2009

Posted by Chris Sullivan in Dive Log, Training.
Tags: , , , , , , , , , , , , , ,
add a comment

I was the first of my group to arrive at the lake on Saturday. There was one car already there, and noticing the tanks inside it, I walked out to the end of the dock to see if I could spot the divers. It looked like they (I hope it was 2 people and not just one) were out by the boat that lies east of the training area at a depth of 30’. At first I saw bubbles, then a diver and then a fin as if he was free diving or trying to overcome a weight deficiency. The water was almost dead calm an crystal clear by Lake Simcoe standards. In any case, they didn’t need any help so I went back to the car to prepare my gear.

Soon afterwards, people started arriving, including my student, Alex, with whom I’d done the deep and search & recovery adventure dives a week earlier. Today we were going to do a Nitrox dive and peak performance buoyancy dive. He’d already used Nitrox on his S&R dive, so this wasn’t anything new, but to get an advanced card 5 dives are required and they can’t be combined. As he was mainly doing the advanced course to allow him to accompany his father on deeper dives on their trips to warmer parts of the world, I decided to take him on deep dive #2 from the deep diver specialty course to give him some more deep experience.

The first thing we did was measure his Nitrox tank, which came in at exactly 30%, so the maximum depth of about 90’ in the area we were diving was well within limits. He set his computer for Nitrox as we’d done the week before. While getting ready, another diver – Neil – showed up who was also doing his advanced who still needed to do his deep dive. He said he’d tried once before but ran low on air and had to turn around. “Walk-ins” at the lake happen all too frequently, and my main concern is having the paperwork done back at the shop, so I asked him a couple of questions about his previous dive to make sure it was recent and done with an instructor I’d trust to have done the requisite documents.

Unlike the week before, I was using single tanks and a wet suit. The water down deep is quite cold at under 10C (50F) which I would normally consider too cold for my 1-piece 6.5mm suit, but reasoning that we’d be at that temperature for less than 10 minutes I decided to give it a try. We swam out to the float which sits at a depth of 30 feet, and descended with reference but not touching it, then followed the line with Alex leading and me at the back. Given Neil’s description of his previous deep dive, I wanted to keep a close eye on him. Alex had already proven to be reasonable on his air and having good trim and movement through the water. He did, however, follow the wrong line and I had to turn him to the correct one. This was understandable as the line going deep was thin and hard to see, while the other line was recently laid and quite obvious.

I could see immediately why Neil’s air consumption was so high. He swam in a head-high position, using rapid short kicks with his knees quite bent and also using his arms for propulsion. On the way down I signaled to him to try to relax and slow down which he did, but I still knew that the time at depth would be short. Once down there we went through the show of colours to Neil (red and orange are supposed to disappear early but like the previous week they were still quite easy to see at 90 feet) and examination of compressed objects (like the Perrier bottle we took with us) for Alex. Alex was also supposed to do a navigation swim (out 20 kicks then back on a reciprocal course) at depth but I decided to work our way back up as Neil was already getting through his air.

Once this was done, we ascended up the line. Both Alex’ and Neil’s buoyancy skills were good and they managed to hold their safety stop without grabbing the line, even though the current was pushing us away a bit. After that we returned to the dock and we were done. I asked Neil if he wanted to join us on the second dive but he showed me a cut that was starting to look a bit ugly after being in the water so long and begged off.

The second dive, peak performance buoyancy was good. Alex’ buoyancy skills were already pretty good, although his knowledge of breath control was limited and I took the opportunity to give him lots of hovering exercises, first at 40 feet then later at 20 feet where it is more difficult. I also showed him the frog kick, which is  useful at that location because of the silt on the bottom. It turned out that he’s not all that comfortable frog-kicking and didn’t do it much. I didn’t press the issue because it’s not on the dive requirements. A little deeper down there’s a bicycle mounted on two poles. This turned out to be great for the “buoyancy game” where obstacles need to be navigated. The first time Alex tried it he came in to high and caught his tank on the pedal gear, churning up silt and making no progress. He finally managed to force himself under it although I thought he might topple the whole apparatus at one point. One his second try it was much better but still the silt cloud was thick after he was done.

Instead of ascending at the buoy we went slowly up the line to do some more exercises, ending up a few feet from the dock for our exit. While the wet suit was more than adequate for our short excursions below the thermocline, the warmth of the shallow water was certainly welcom.

Meanwhile Marty was teaching a rescue class and Matt was conducting a dry suit specialty course, then an open water student showed up needing to do dives 3 and 4, and another came along wanting to do dives 1 and 2. They asked me if I could stay to help with them, and also to come the next day and help, but as I was going away to Brockville the following weekend for the wreck course, I told them I had done all I could for the weekend, and I had to leave it to the other instructors to work things out.