Conditions were beautiful on Sunday. John and I saw the excellent progress the carpenters had made on the bot house in nasty weather on Saturday. We chipped a significant amount of ice from the hole, recovered the instrument, and headed back to station. The Mechanical Equipment Center has outfitted us with a diesel-powered heated glycol pump, called a hotsy, to help us keep the hole from freezing in. Britney, Justin, and Josh used it to melt back about 8" of radial refreeze on Monday, making the hole ready for Sunfish operations this week.
Back on station, I've plotted the water current data we collected over a tidal model. There's quite a bit to say about the plot (below), but the most important thing is that low current velocity at our site is correlated in time with rising tidal amplitude. Tidal amplitude is predictable, so we should be able to plan our robot dives at low-current times of day, minimizing the amount of energy the robot has to spend swimming upstream.