We limped back in on one engine.
An odd sound alerted Dennis to something amiss, a chuffing sound that the engine does not normally make. Opening the hatch showed more trouble, the engine had dumped all its oil into the bilge. It could be something bad, or something really bad, no way to find out without taking things apart, not something we were not prepared to do.
Already moored at the dive site buoy we decided to forget about the engine, at least for a little while, and do the dive.
Conditions were decent, but not great, some surge was stirring up the water. Faint echoes of whale-song could still be heard, probably the last we will hear this season.
Just underneath the mooring at Pentagon is a wonderful complex of caves, this was where we spent much of the dive. This is a great dive site, a shallow coral plain pocked with numerous caves and small sandy areas. It is a good place to look for invertebrates, big and small. The caves shelter nudibranch and other small critters. The sand patches are home to one of the largest invertebrates found on Hawaiian reefs, the horned trumpet snail.
I located a species of nudibranch that was new to me, the snow-goddess nudibranch (Ardeadoris poliahu). A pretty animal about 4cm long among the algae covered rock in a cave. The nudi was nicely positioned on a boulder in a cave, no problem to photograph, except for the surge sweeping me back and forth. I also found a gold-lace nudibranch that was well positioned for photography. I got some good photos, so did Pete when I showed him where to find the critters.
We would head home on a single engine without making a second dive for the day. Never having done this we all wondered how fast we would go on a single engine and how long it would take to return to harbor. We were a long way north, over twenty miles up the coast from Honokohau, the absolute worst time for an engine to fail. Everyone good for docking at midnight? Would we all make it to work tomorrow morning? Our speculation was for naught, we could manage seven knots without straining the remaining engine, we could return to harbor in good time.
The trip back may have been a bit slower, but this was not a problem either. There were humpback whales along the coast. We had good views of several groups as we traveled, including a couple nice breaches right off the bow. Another group, a mother, calf and escort played about in very shallow water at Makalawena. It was just a nice day to be on the water, nobody was in a real hurry to get back to harbor.
The trouble with the engine has turned out to be fairly minor, the oil pressure switch failed, allowing the engine to pump itself empty of oil. A quick and inexpensive fix, but a real mess in the engine compartment.