The Yukon is a 366 foot Canadian destroyer brought to San Diego for the purpose of sinking and creating an artificial reef for wildlife & divers (if there is a difference).

The Yukon sunk prematurely when it was towed out to it's final resting place because large swells that evening entered the large holes cut in the side of the ship. As a result the ship is sitting on it's port side on the sand, instead of upright as was intended (oops).

For more info, http://www.cawreckdivers.org/Wrecks/Yukon.htm
http://www.divebums.com/Wrecks/Yukon/index.html