Blackbeard's Crew and the Yacht Society

The yacht club, out on a cruise, is attacked by pirates, headed by a man who might be the very reincarnation of Blackbeard himself. Batman and Robin intercept a message from the yacht about the pirates, and go to investigate.

When they arrive at the yacht, the pirates get the jump on them. Robin is made to walk the plank, and Batman dives after him. The two are attacked by a tiger shark. There's no bat-shark-repellent this time: Batman fends the creature off with a blade. The two return to the yacht to rescue the captives.

During a fight, Batman and Robin take up swords, and Batman says: "Use only the flat of your sword, Robin! Remember, we never kill with weapons of any kind!"

At length, they win, and Blackbeard is revealed as the gangster, Thatch, in disguise.