Day 2 in the habitat. It was strange to sleep last night; as the waves pass overhead, they change the pressure in Aquarius (yes, a small swell affects us, even 50 feet below the surface). This means that we have to keep clearing our ears. Just a little bit, like the first moment after ducking your head in a pool, but during the night it can be a bit disconcerting.

Other things are strange too. the sounds, for one thing. There is an occasional rumbling gurgle; this is air spilling out of the moon pool in the wet porch. Air compressors located on the Life Support Buoy keep a small amount of air flowing through the habitat at all times, and it spills out from under the wetporch ledge. then it rolls up the side of the habitat with a great clatter. Another sound that took a while to understand is a dripping sound. Since there is a good deal of water around, this naturally made me (as the only one here for the first time) a bit curious. Is this a bad thing? Turns out that the noise is snapping shrimp that live all over the habitat. These creatures use one of their claws to make a powerful sound underwater. powerful enough to reverberate through the thick steel hull and certainly enough to stun their small prey (which is why they are making the sound) and allow them to eat.

Today had its ups and downs (scientifically, that is.everything else was great). We got a strong start on our experiments, getting the cables run out to our research site, everything plugged in and seemingly working. We also got the first set of plaster models deployed and Chris and Brian made lots of flow measurements. So far, so good.

Then, of course, the downs. We tried to go out to begin making measurements of the oxygen levels above corals. This involves moving a very fine, fiber-optic probe near a coral head. After we had the whole thing plugged in and going, Chris noticed that the fiber was cracked... oops... back to the habitat for another (a long process to switch and calibrate the new probe). Hopefully, that won't happen again, since the probes are rather expensive and we don't have many. To add insult to injury, we found that the computer had been lying when it said it was recording the flow velocities Chris and Brian spent their afternoon on. Drat.

A huge plus, however, came over e-mail. We had been trying to get brass models to measure the flux of heat to different shapes. This will be analogous to the rate at which nutrients are transported to corals of different shapes. Unfortunately, a supplier who was supposed to cast these models fell through at the last minute, leaving us in the lurch. Enter an amazing friend from Stanford who whipped them out as a project in his Product Design class. Thanks to Luke and the PRL for the huge effort! FedEx should now be on the job of getting them to us (I'm picturing a white submarine with the logo on the side, but they will actually deliver to the NURC office, and the staff there will dive them down to us!). That was a huge boost to our efforts.

Things are looking great for tomorrow - Dean and Chris fixed the O2 probe and the computer glitch. In fact, we all expected such problems; they are just part of science (which is why we have spares of every component that we can afford to have more than we need). Now that these hurdles are out of the way, we are primed for a productive day tomorrow.

Another great item today: Dean and I were just finishing our dive, about to head back to the habitat. Dean turned to make sure that we hadn't forgotten anything and then grabbed my arm. There, swimming slowly above our experiments, was a small sea turtle. I dearly wished that I had a video camera as it seemed to inspect one piece of our gear (actually, it bumped into it as Dean and I watched in amazement). Seemingly unconcerned, it swam directly at us... surprisingly fast for a turtle. We both hung motionless in the water as the turtle swam within a foot of Dean and then went about its business. It was a real treat.

Tomorrow is more of the same. We will hit the water at about 8:00am, with plans to spend 4 to 6 hours out of the habitat in the water.