He is waving his arms in the vain hope that his friends will see him. The boat is listing to the back as the octopus pulls the diver further into the cave. This is the second collection of The Far Side comic strips.
All comic strips are in black and white.
These are all single shots, not the normal 4 panel comic strips. The Far Side is a humorous comic strip that appeared in a multitude of newspapers daily. The Far Side became very popular in the early1980s, and continued into the 1990s, until Gary Larson decided that he was going to retire the comic strip. It was seen daily in hundred of newspapers and enjoyed by millions. Most of the strips feature humans, but not all.