I just came home from four absolutely wonderful days of diving with dear friends in Monterey. We planned some technical diving, and some recreational diving. There were three of us on the trip, and two were able to field two sets of doubles each, which we brought down with the appropriate mix. But I only own one set of 85s, and Peter was using my HP100s. All we had left was LP72s, which I loathe . . . so I asked my friend in Monterey if he could acquire a set of LP85s for me, and he said he could.
I arrived in Monterey, and we set up for the first dive. These 85s were odd -- much thinner and longer than mine. (Turns out mine are Worthingtons, and his were Fabers.) I went down to do a staged decompression dive with these tanks, and realized on descent that I was somewhat underweighted. In addition, they balanced completely differently from my tanks, and I was head-heavy and unable to be still. It was not a problem during the bottom time, as we were swimming at least slowly most of the time.
But on ascent, it did become a problem, because I couldn't stop sculling, and kept running into one of my buddies. In addition, the underweighting issue got uncomfortable at 20 feet (which, of course, was the longest stop) so I spent the entire 8 minutes or so swimming down, and swimming in circles, and irritating my buddies.
The following day, in my own tanks, I was back to being a halfway competent tech diver.
Lesson learned: Inquire as to the brand and buoyancy characteristics of borrowed tanks, especially if you are going to use them for a dive that's on the edge of your sphere of competency or experience.
I arrived in Monterey, and we set up for the first dive. These 85s were odd -- much thinner and longer than mine. (Turns out mine are Worthingtons, and his were Fabers.) I went down to do a staged decompression dive with these tanks, and realized on descent that I was somewhat underweighted. In addition, they balanced completely differently from my tanks, and I was head-heavy and unable to be still. It was not a problem during the bottom time, as we were swimming at least slowly most of the time.
But on ascent, it did become a problem, because I couldn't stop sculling, and kept running into one of my buddies. In addition, the underweighting issue got uncomfortable at 20 feet (which, of course, was the longest stop) so I spent the entire 8 minutes or so swimming down, and swimming in circles, and irritating my buddies.
The following day, in my own tanks, I was back to being a halfway competent tech diver.
Lesson learned: Inquire as to the brand and buoyancy characteristics of borrowed tanks, especially if you are going to use them for a dive that's on the edge of your sphere of competency or experience.