Some time ago I build a tray and handle for my Ikelite underwater housing, which allowed me greater control of the camera underwater. This worked pretty well, but there were drawbacks. The handle was an aluminum bar (1/4" thick by 1.5" wide by 8" long) attached to the housing with steel machine screws. The handle was a section of "loc line" commonly used to hold underwater video lights, wrapped with vinyl to create the handle. The machine screws rusted, the aluminum was starting to corrode under the loc line attachment, and the overall 'feel' of the handle underwater was not optimum. Also, the handle interfered with the housing fasteners meaning it had to be removed to open the housing to insert/remove the camera every time.

Then this month I purchased a Light and Motion SOLA 1200 underwater video light. This thing is AMAZING! It has enough power to light my videos and even act as a main light source for still photography. The narrow beam is good for signalling or peering into small dark places. The three levels of power allow me to tailor the light and battery life to the needs of the dive. The light is very compact and light, and charges quite quickly. Overall a great addition to the photography gear.

The light came with a loc line attachment, which ended up triggering the decision to remake my tray/handle. Basically, I wanted a more proper handle to hold the loc line. As I was going to build a new handle, I could address the location of the handle in relation to the housing clips. Checking measurements and fit, the new handle would be a single piece of Stainless Steel, 1.5" wide by 15" long (8" + 5" handle + 2" light mount). Tough choice on thickness, but the SS was inexpensive so I bought both 1/4" and 3/16" thick pieces. As it turned out, I was unable to bend the 1/4" SS at home, but was able to form the new handle out of the 3/16" SS without much difficulty.

The final result, including the mounted SOLA 1200 light can be seen below. Now to go for a dive this weekend!

Shortly after my Prism training, I replaced the stock recreational harness with a backplate and wing. This required modifications to some harness elements, specifically attaching the counterlungs to the harness. At the top (shoulders), I used a purchased "Prism counterlung backplate yoke", which has worked perfectly. At the bottom of the counterlungs, I modified the stock adjustment straps to fit on the harness waistband. This has worked very well from 2007 until November 2011.

Recently I've been noticing that the placement of the lower straps can dramatically affect the operation of the diluent addition valve. On my most recent dive, the strap slid to the side while gearing up which resulted in the diluent valve operating every breath. This increased diluent use for the dive. Time for a change.

My buddy Mike Burgess also dives a Prism, also with an almost identical harness. Mostly the differences come down to where we bought our 'bits'. However, Mike did not use the lower straps, but has always used a bungee with dog clips attached to the harness crotch strap d-ring to hold the counterlungs in position. Mike reports this is not only more snug during the dive, but he does not have to adjust straps, and the counterlungs being drawn to the center of the body always sit in optimum position.

As a result, I have now built a similar bungee & dog clip counterlung attachment rig. First dive to test this will be this coming weekend.

I've been using Grace Sodasorb 6-12 since the very beginning with my Prism. This is the sorb that was recommended by the manufacturer and my instructor, so why switch? Well, it's getting harder to obtain, it's very dusty, and it's now about twice the price of Sofnolime 8-12. Mike has been using Sofnolime for some time now, and reports the work-of-breathing (WOB) is unchanged by the switch, scrubber life is the same (perhaps longer), and the cost cannot be ignored. For me, another feature is that Sofnolime is the stuff carried locally and used by every Meg diver in the area. Sounds like a done deal.

I have owned six dive computers and/or bottom timers since I first started diving. I have four of them right now.

Suunto Octopus II

My first dive computer was a Suunto Octopus II, bought in May 2000. It was inexpensive (compared to many in 2000) and did the minimum required for my diving at the time. It would not calculate deco, nor would it accomodate anything except air as the diving gas. In fact, if you did go into deco with the computer, it would simply say something like "stop 20ft" (I cannot recall the exact message) until the computer cleared the deco obligation.

This proved to be somewhat worrying during my TDI Deco Procedures course in 2001 at Sechelt on the Sunshine Coast of B.C. On one of our dives to around 150 fsw, the deco obligation was significant. Other dive computers on my buddy and instructor had long cleared, and we were about to ascend 'anyway' when the Octo II finally cleared. In the end, everyone else had around 5 min. at 20fsw while I ended up spending almost 12. After that dive, I decided that I required a better dive computer - one that could handle Nitrox and decompression.

OMS Bottom Timer

For the Deco Procedures course I bought an OMS Bottom Timer as my backup timer. I bought it in March 2002 I still have it. It stays in my dive bag just in case one of my primary computers fails, which has happened on at lease one occasion. What can I say... inexpensive, and it works.

My third device was a Suunto Vyper, also purchased in March 2002. This is a fairly decent dive computer. It can handle Nitrox blends and can calculate and display deco stops using the chosen dive gas. I only sold it when I moved towards the DIR style technical diving and replaced the Vyper with...

Suunto D3

A Suunto D3, purchased in October 2005. I think this has dive computer functionality, but I honestly don't know and don't really care. The day I bought it, I switched it to guage (bottom timer) mode, and it has been that way ever since. Up until yesterday (Feb 12, 2011), it was my primary timing/depth device on every dive due to the readability of the display and clarity of information. I also very much like the ability to download my dives to the PC and view them. I had to buy the special USB cable, but it has paid for itself over and over.

I continue to use the Suunto D3 as a primary dive guage on all dives. It is my backup to the primary deco computer, a Shearwater Predator.

Cochran EMC-20H

My fifth dive computer came 'free' with the spare PRISM Topaz that I purchased from Drew Reed in April 2008. This was a Cochran EMC-20H with Nitrox, Helium and Closed-circuit Rebreather modes. This is the 'top of the line' Cochran, and is a full dive computer able to calculate and display decompression information for either open circuit dives (including nitrox or trimix) and closed-circuit rebreather dives (also nitrox or trimix). Although Drew included it with the PRISM, I ended up spending quite a bit of money after the fact. First, I bought the 'pro' version of the PC software, thinking it would allow me to update the diver info on the device (it does not - only a dealer can do that). Then I spent quite a bit upgrading the memory and battery. This started quite a process, as the engineer said my serial number device could be upgraded, only to tell me it couldn't after it arrived. Joel Silverstein of Tech Diving Unlimited proved to be invaluable in helping me get the upgrade without having to buy a whole new computer.

Unfortunately, the new upgraded Cochran did not behave well. After the very first dive, it blew it's battery cap across Ken's boat! The battery was foaming and I had quite a cleaning job. On the very next dive (new battery, all clean and tested in the sink) it did the same thing. I sent it back, were a very fine hairline crack in the case was determined to be the culprit, allowing salt water to enter the battery compartment at depth. Cochran sent me a new computer. This one worked very well for many months, until I noticed the display was cracking around all the screws that hold it on. I sent it back again, and it was returned as good as new (March 2010). Currently the computer looks just like brand new, and I've been diving it on every dive until just very recently, when the Shearwater arrived.

The nice thing about the Cochran is it has a great (large) NDL display, and calculated deco that has been perfect for me. The only downside of the Cochran is that it's still rather hard to see at depth (as is the D3 and the OMS), and you cannot switch from OC to CC during a dive. That is, you can't 'bail out' to open circuit on the computer if you have to bail out during the dive. The solution according to many is to use 36% EAN as bail out gas, as the deco for that gas is pretty close to the CC decompression when using 1.3 as the bottom PO2. Still, hardly optimal.

Shearwater Predator SPOCT-SA

My current dive computer is a Shearwater Predator SPOCTSA, purchased yesterday. It is a nitrox / trimix (helium), open circuit and closed circut computer without the Fisher connector (the SA means stand alone). The Fisher connector is to allow connection of the computer to the O2 sensors in the rebreather. Since that is not realistic for a PRISM, the SA (no connector) was perfect for me. It features an OLED color display that is just simply amazing. It calculates deco profiles during the dive for both closed circut and open circuit, so you can bail out from CC to OC at any time and the deco profile is already 'in process'. It's also super easy to program and operate, on land and under water. (the other computers like the Cochran are much easier to program via the PC link and PC software than using the device buttons).

I am currently using the Shearwater PROCTSA as primary deco computer, and the Suunto D3 as my backup bottom timer. It was so wonderful to be able to SEE the computer clear as anything at depth! Both the Shearwater, the Cochran and the Suunto can all be downloaded to the PC, which I really like.

Some longer deco dives demonstrated that the Shearwater GF deco algorithm is excellent and I am very comfortable diving with this computer. I'm currently using the default gradient factors of 30/85, which give a good deco profile compared to the Cochran.

Based on deco algorithm, upgradeability, visibiliy underwater and sheer beauty of operation, it is clear I no longer require the Cochran. Fortunately, it was sold very soon after I posted it on the on-line forums.

My Prism Topaz was purchased new in March 2007. I received the unit and trained on it in May, 2007. I have been diving the unit pretty much steadily since then. In April 2008 I purchased another (used) Prism from a fellow in Washington State, mostly for spare parts. I did dive that unit once to ensure it was working properly, but it has been in storage since then.

Over the past four years, I have had only a couple of problems with my Prism. One was user error, the other wear and tear.

The user error issue involved laying the Prism down on top of the HUD after a dive. I had finished rinsing the unit and was placing it on my disassembly table when I overlooked the HUD laying under the unit. I managed to snap off the plastic bolt that holds the HUD to the mouthpiece assembly. A call to Steam Machines (SMI) provided me with replacement bolts, and the assurance that this part was intentionally designed to break in such a situation - preventing more catastrophic (and expensive) damage to the HUD itself. I have not yet replaced the broken bolt; rather I've been diving the HUD from the second (used) Prism.

The second problem is more wear and tear. The cable between the secondary display and the head is starting to show signs of 'wire fatigue'. Under certain circumstances (ususally during set up), the reading for cell #2 will drop to zero if the cable is flexed a certain way. Repositioning the cable always restores the sensor reading. It has never given trouble during a dive, and the secondary reading does not affect actualy operation of the sensor in the head electronics. I have called SMI about this one, and will have the cable replaced in the near future. If necessary, I can always switch to the secondary in my backup Prism.

Other that these two items, everything else has been routine maintenance and consumable replacement. Cells last on average about 18 months if they are new when installed. I did have a few issues with installing older cells (purchased new but stored for some time). However, new cells give no such problems. I have also replaced the main head-scrubber bucket d-rings as they wear and no longer seal during the negative pressure test. Again, probably about 18 months for a set.

Otherwise, the unit has been a champion. It has consistently supported me diving both long and deep. I love the pre-dive procedures that allow you to prepare the unit before the dive in comfort and serene circumstances, then peform a simple pre-dive just prior to donning the unit and diving.

In July 2008 I purchased an Armadillo CCR sidemount set for my Prism. This consisted of a butt plate with tank mounting rails, bungees and a bungee mount strap. I also purchased some tank bands for the bailout tanks. Since that time, I have completely converted my bailout from normal stage mounting (2 clips on the harness) to sidemount (one clip on the butt plate plus bungee). From the first dive, I liked the sidemount setup. I have now been diving it for the past 2 years and still find it a nice combination of easy to use, good underwater balance and trim, and nice streamlining.

In the photography link I described the Canon A570IS combined with the Ikelite housing, purchased in November 2007. I still love the camera and housing, and take it with me on every dive except when I'm teaching SCUBA. It continues to take excellent pictures and great video. I stopped carying my HID light and switched to the Tri-LED Greenforce some time ago as it has no 'hot spot' and thus is a great video light for the system. I still do not have any flash unit other than the built-in flash. The Greenforce does double duty as a fill-in light on some photos. Since purchasing the system, I have built an aluminum tray and flexible arm to hold the Greenforce light head in position when shooting longer videos. The light attachment still needs a bit of work, but overall it is a great system.

The Jetsam Baby Booster, purchased in June 2007 continues to transfill and boost Oxygen without problems. The original drive compressor, a Dewalt oil-less unit, died in March 2010 after at most 25 hours of use. The motor commutator was fried and not replaceable, so they gave me a refund thanks to the extended warranty. I took the money and bought a Porter-Cable unit that was comparable but has a significantly larger pressure vessel. I'm hoping the larger capacity will provide drive gas with less compressor cycling (duty cycle), thus increasing compressor life.

The Alkin high pressure (4500 PSI max) compressor, purchased February 2008 continues to work well. It certainly does not see significant duty, being only called upon to fill my 19cf tanks on a regular basis as well as the 6cf suit gas bottle. It also occasionally tops up the 40cf and 80cf bailout tanks. In that, it has been a solid unit.