Wow, so much has been going on, and I haven’t posted any of it.
I’m finally picking up my Divemaster Certification through Ocean Adventures Dive Co. So far we’ve only completed the knowledge reviews and watched a cheesy PADI video. We take the written tests on Thursday and then spend two full days in the pool that weekend. Wish me luck!
In other news, I bought a 40 cubic foot Luxifer aluminum stage bottle about a week ago. That may seem like a strange purchase for someone who still hasn’t purchased a set of doubles, but let me explain. After diving the Oil Rigs for the first time, I’ve been more excited about deep dives (110 to 130 feet). Last time i dove the rigs, the deeper I went, the wider the visibility opened up, so naturally I wanted to go as deep as I safely can. This has posed a bit of a problem because I’m now using absolutely all of my no decompression time, and ascending with a much leaner nitrox blend in my tank for off-gassing during my ascent and safety stops.
As crazy as some of my dives have been in the past, I try to remain conservative with my gasses. I follow the GUE standard of no more than 1.4 PPO2 when active and 1.6 while at rest on a decompression stop. That means that during my bottom interval at 130 feet, the maximum bled is 28.34% EANx. Calculated as [(depth in feet/33) +1]*F02=PPO2. That doesn’t give me much to work with as far as NDL or as far as off-gassing on a stop. I was researching doubles when I realized I can get almost as much air as double 80′s by simply adding a 40 cf bottle to my existing 119 cf back gas. An added benefit of going this rough is that it gives me the option to breath a higher concentrations of oxygen during my ascent and decompression than the mix I use for my bottom time.
I have to admit economics also led to my decision to put the cart before the horse in the way of a stage bottle. The Luxifer 40 ended up costing me roughly $200 for the tank and $35 for the rigging. To make the switch to doubles I was looking at around $1100 for the tanks, manifold, and bands, and another $350 for a new wing. Don’t get me wrong, I still plan on buying the doubles and all the extra gear that goes with them, but for now I can get some extra bottom time and some valuable practice switching gasses for when I do get serious about technical diving.
So how about those Oil Rigs. Some friends and I are back on the Sea Bass this Sunday. Hopefully I will have some good pictures to share and a few stories on Monday.