We are most of the way through our transit back to French Frigate Shoals, armed with the latest GPS, Sonar, charts etc. The French explorer LaPerouse had none of these navigational aids in 1786, when his two frigates approached this very same atoll at night. He and his men replicated much of Captain Cook’s voyages, crossing the Pacific multiple times, with stops in Alaska, California, Chile, Russia, Japan, Maui and many more locations. What he did have was keen lookouts, who spotted the surf breaking on the reef at 1000 yards, and prevented disaster by alerting the helmsmen to come about. The French explorers returned at daylight to survey the atoll, before continuing west. LaPerouse left his name on the Pinnacle, which is the oldest surface rock in the Hawaiian island chain, and an important seabird rookery. Because of the frigates, avoiding the shoals, and being French, we are headed this evening to French Frigate Shoals. The pinnacle looks from a distance somewhat like a ship in full sail, and like a siren, has allegedly lured other lonely mariners into the shallow reefs as they closed to investigate.
The crew aboard Hi’ialakai uses transit days to conduct maintenance, although a weekend transit day means a short day for the crew, and a fairly relaxed atmosphere. Like the other deep divers, I serviced my rebreather, and took the opportunity to take a picture of the main parts for those not familiar with the little submarine. We don’t do very much tear down between dives, mostly rinse and dry, and replace the consumables. We swap out the CO2 “sorb” material every two dives, due to the relative short nature of our dives – total run time is less than 90 minutes. We top off the oxygen and diluent every day, and analyze the gas mixtures to make sure that the computers that calculate our decompression times have accurate data for their computations.
A day on the cruise wouldn’t be complete without more seabird pictures, so for those twitching with anticipation, I reveal my best shot yet. Two Red-footed Boobies were enjoying a free ride on the wind vane / bow light mast on the bow. One had a precarious perch, as he snuggled up to the spinning propeller of the wind vane. He lost purchase and then circled many times to attempt to land again for his free ride. The circling allowed me to be ready for a predictable point to shoot the moving, wheeling bird from a pitching deck with a long lens.
A project that I have been peripherally involved with is the monitoring of acoustic receiver data sent from transmitters implanted in sharks and large reef fish. Researchers from the Hawaii Institute of Marine Biology have an array of sensors throughout the entire archipelago. The receivers need to be recovered periodically to download the data and replace batteries, a task which often falls to eager graduate students from the Shark and Fisheries Research group. A challenge arose however, as the receiver needs to be placed at 150’ deep, and the students are only cleared to dive to 130’, less when diving enriched air gas. The solution is this improvised anchor, which I call “The shackles the result from bad vices”. According to the new math, this slag should counter the buoyancy of the float that ensures the receiver remains in a vertical orientation to best detect receiver transmissions.
I am on the afternoon deep dive team, which means a leisurely morning to get ready. I am unaccustomed to only one short dive a day, and I should have time to begin and continue my intended projects, yet seem to fill my time with avian interests and preparing for Johnston Island, which all aboard are eagerly anticipating.