183 days

Graves Light

I put together my rebreather in the den. Every piece was there, just as I had packed it after Bonaire. I sat on the floor, pulled each part of my beloved X-CCR gingerly from its padded box, and built the unit piece by piece. I blew into the loop, and the unit held positive pressure. I sucked air out, and it held negative pressure. The seals were holding. My unit was complete. All systems go. 

I turned on the dive computer that was hard-wired into my rebreather. The display lit up. In the upper right, the computer displayed my surface interval: 183 days. 

Ouch. 

I knew it had been several months since I was in the water, but somehow, seeing the number of days - in the hundreds - made it seem even longer. It was definitely time for me to travel beneath the waves again. 

I drove to Boston in the early morning, loaded my gear on a charter boat, and headed out to Graves Light. The lighthouse, situated at the entrance to Boston Harbor, was surrounded by a rocky outcrop covered in marine life. I felt at home as I swam among the swaying red algae. Nudibranchs covered the wall of one boulder, and I even found a sea star (Henricia sp.) among some gravel. Most of my body was covered by a waterproof drysuit, but the cold ocean water felt invigorating and refreshing on my neoprene-clad head and hands. 

Only one thing bothered me as I swam along. Every time I stopped kicking for even the slightest second, my head tilted downward. I could feel the foot-end of my drysuit filling with gas as my center of gravity shifted, and I started to worry that I'd be ripped up to the surface by my bloated feet. I pulled my feet back under me and released some gas from my suit. Then I started to sink. The problem was not the overall volume of gas I was carrying, but rather its distribution. In diving terms, my trim was bad. 

At the pond

My mind flashed back to Bonaire. I had worked on my trim with an instructor, and we had made some adjustments to my rebreather that added buoyancy near my hips. That must be the problem, I thought. Those tweaks we made in Bonaire were perfect for diving in my wetsuit, but the drysuit was a different beast. In my wetsuit, I was foot-heavy, but the gas-filled drysuit added more than enough buoyancy near my feet to compensate, leaving me head-heavy instead. The two situations required completely different strategies. 

I needed to work on my drysuit trim - and a lighthouse in the middle of Boston Harbor was not the place to do it. Thankfully, there's a pond just about an hour away from my house that offers an easy shore entry. At the pond, I could get in and out of the water a dozen times if I needed to, tweaking and testing my gear set-up each time. 

I headed over to the pond a few days later, on a sunny afternoon. On the shore, I could adjust my weight belt, move the gas bladders of my rebreather up or down, and tinker with my unit as much as needed. Thankfully, it took only three tries to get my trim right. I slipped under the surface, kicked forward once, and could immediately tell that I had nailed it. The swim was effortless. I hovered, weightless, perfectly parallel to the sand. I felt satisfaction and a deep sense of joy. 

Diving is my all-time favorite thing, and as I take on more advanced dives, it becomes even more important to dial in the details like trim. With my rebreather perfectly set up for drysuit diving, I look forward to a good summer season!