Andrew Lost On the Reef — J.C. Greenburg

ANDREW'S IN AN UNDERWATER MAZE!
Hot on the trail of the giant squid, Andrew, Judy, and Thudd smash their underwater vehicle (a.k.a. the Water Bug) into Australia's Great Barrier Reef -- home to some of the world's most dangerous creatures! Then their arch-enemy, Soggy Bob Sloggins, steals the Water Bug. The kids must find their way through the reef and get the Water Bug back -- before those deadly creatures start to nibble!