We're now well into our mission. Our fingers are wrinkled and I feel kind of soggy. But we've slipped into a type of routine, and the underwater-ness of our days is beginning to feel natural. If I could have one thing, I think it would be a mucus covering, the kind that fish and anemones have, as my terrestrial skin is feeling the wear of 8-10 hours in the water, in a wetsuit. Before each dive I put tape on a few of the areas that have been rubbed red by the bending of my joints in my wetsuits- inside my elbows and behind my knees, also on my upper arms, at the armhole of my suit. That seems to do it.

We're running a nutrient enrichment experiment on the grating of the habitat. We've got three chambers that we spike with nitrogen, and run incubations with a thallus of the green alga Codium in each of the chambers. They run for 4 hours, then we start the next one. We've been doing 2 runs in the day and one at night. The algae from the incubations are put in labeled bags and picked up by our surface crew. They take them back to the lab and dry them. They will be analyzed back at UC Berkeley campus for nutrient concentrations. This will, hopefully, tell us if the algae are able to make use of the pulses of cold, nutrient rich water of the internal bores that slosh onto the reef.

We're also running transects to determine the distribution of algae across depth. The Codium at the Deep S-4 site on the sand is big, much bigger than on the reef spurs. The flow probes are positioned over coral heads to characterize the water flow over the surface of the reef, and current profilers are recording the flow up in the water column. We take water samples when we feel the temperature of the water dropping, and these samples are also picked up by the surface crew, filtered and frozen, and sent to Miami for nutrient analysis. We're busy, and on the long swims out to our sites we see the daily goings on of life on the reef.

Yesterday, clouds of sediment billowed out from the sand channel one over from where we were working. We made puzzled faces at each other through our masks, its rare to see such a commotion. We cautiously peered over the reef and when the sand settled, we saw a large Southern stingray snuffling down in the sand in search of invertebrate goodies. This morning a lizardfish held an odd pose, fins splayed it sat still on the sand. It took a while to see the small blue and white cleaner shrimp working like mechanics, removing something from the scales and fins of the fish. When the shrimp moved to the gills, the lizardfish splayed its gills open and the shrimp crawled in, then into the mouth of the fish, all the while cleaning, and the fish motionless and obliging. It's quite an amazing relationship to observe.

There are also Caribbean reef squid that seem to have taken up a spot on one of our temperature loggers. Sometimes there are many, up to 10, sometimes just 2, but they are there when we swim past. Initially, they raised their 2 arms up at us, a warning signal, or to make themselves look bigger and more menacing than they are (although they are only about 5cm long). When I brought the video camera up to film them, they encircled me, always facing toward me and equal distance from one another. They change their color, to match their mood it seems, as their fins ripple down their bodies, faster as I approach, slow as the distance between us increases. But after we had passed several times, they just hovered against the logger, shimmering iridescent lavender, blue and brown.

It's getting late, at least for how tired we feel. The water saps out energy and we fall into bed, usually by 10:00 PM. We've got our night algae incubation running now, so that will involve a quick hookah (air supplied from the habitat through a long hose) excursion to stop the incubation at 11:30 PM. The dip into the cool inky water in the lights of the habitat feels like a spaceship as the plankton wafts by in the current and Aquarius belches huge bubbles that race up its sides to the surface.