The male of an undescribed basslet in the genus Pseudanthias at a depth of 300 feet (90 meters). Photo: Richard Pyle.

The male of an undescribed basslet in the genus Pseudanthias at a depth of 300 feet (90 meters). Photo: Richard Pyle.

It was another late start today, but certainly not an unproductive one! In the morning Brian, Sonia and I met with with Eugene Joseph, director of the Conservation Society of Pohnpei. We are thoroughly impressed with this organization, and we are very much looking forward to collaborating with them on this and future projects. After that, we finished filling our emergency bailout tanks for use on the remainder of the project. Such is the nature of our deep diving that the vast majority of time spent on logistics is for filling scuba cylinders that almost never get used.  But of course, in the very rare case that we do need them, they mean the difference between life and death.  We were further delayed by some rebreather issues. Our rebreathers have a very sophisticated oxygen sensor validation system which becomes extremely sensitive with low fractions of oxygen (in this case, our rebreather diluent cylinders contained only 6.3% oxygen). If we don’t get the mixture analyzed correctly, it’s very difficult to pass these sensitive tests. Tomorrow we will increase the oxygen content of our helium mixtures to avoid the problems in the future.

Today we did our first deep dive using helium mixtures.  On all of our expeditions we like to ramp our way up to the more serious dives, so today’s plan was just to perform a quick reconnaissance of the deep drop-off south of Palikir Pass. Sonia, Brian and I made a quick “bounce” dive to about 100 meters (330 feet) to scope it out, while Dave, Garrett and Richard Coleman a somewhat shallower work-up dive to 170 feet (52 meters).  The water was very clear, which means the deep reef was very brightly lit. Other than an extremely large sea fan (gorgonian coral), there was not much relief on the bottom.  The steep slope gave way to an precipitous drop-off another 50 feet (15 meters) below us, but we decided not to push our luck (especially given the late departure time).

During my very brief bottom time, I got some decent video of two species of fishes that are new to science.  One is a beautiful basslett that Brian first discovered many years ago in the Marshall Islands (in the same complex as Pseudanthias engelhardi and P. carlsoni). The other, is a damselfish in the genus Chromis that has also been seen and collected by Brian in the Marshall Islands, which is similar to C. brevirostris but completely lacks any yellow (apologies to the non-fish-nerd readers — I need to address a broad spectrum of interests in these posts!)

An apparently undescribed damselfish in the genus Chromis at a depth of 300 feet (90 meters). Photo: Richard Pyle.

An apparently undescribed damselfish in the genus Chromis at a depth of 300 feet (90 meters). Photo: Richard Pyle.

The decompression was uneventful and relatively short (my total time in the water was just over 90 minutes). More eventful was our attempt to drive the boat back to Nihco Marine Park, when the pull cord broke on our outboard motor.  Fortunately we had arrived in two boats, so the functional boat began towing us back to shore.  We managed to fix our engine while under tow, and safely motored our way back to shore well before sunset.

Brian Greene and Sonia Rowley decompress on the reef beneath one of our two dive boats. Photo: Richard Pyle.

Brian Greene and Sonia Rowley decompress on the reef beneath one of our two dive boats. Photo: Richard Pyle.

As I write this it is 11 pm here in Pohnpei.  We are planning an earlier start tomorrow, but I decided it was important to get this post uploaded before calling it a night.  I wouldn’t want to cause any undue concern for my good friend Nigel Jones, who became very worried seventeen years ago when I missed one of my daily posts during the 1997 Palau expedition (see Nigel’s comment on yesterday’s post).  Besides…. who needs sleep anyway? (Just teasing, Nigel — I would be up this late no matter what….)