A gentoo, perhaps looking for rocks
Then, another penguin came from the other direction, and they met right in the middle of this narrow passage between the standing objects. They looked at each other, then began a strange parody of Japanese gentlemen, bowing to each other cautiously and repeatedly, over and over. I'm not sure if they were trying to vie for rocks in the cluster, or trying to determine precedence somehow, or trying to decide who should get out of the way. They just stood their bowing to each other.
Eventually, one of them (the newcomer, I think) gave up and turned around and left. The remaining one laid down on its stomach on the rocks and stayed there for a while.
There were a small number of large, dark brown birds with white spackles on their wings flying over the rookery. When they got too low over a group of Gentoo with chicks, all of the parents angled their heads up and squawked violently at the bird to frighten it off. I later saw these birds flying low around the water behind the ship, landing on the water briefly and searching for fish.
A bird near the ship, of the same variety that harries the gentoo rookeries