WWII-era bookkeeper--hopelessly near-sighted and strictly 4-F with the Navy--changes into a fish and aids the U.S. battleships in an attack against Nazi subs. Though it takes forever to get going, this is a harmless, mindless, partly-animated diversion for children. Probably the most popular of the Don Knotts vehicles of the 1960s, and indisputably the best-produced of the lot; however, with Limpet an underwater success as a military 'secret weapon', his insistence on gaining recognition, compensation, and a lieutenant's ranking for his work coats the product with an unattractive cynicism. The animation is better than it had to be, though the interiors are overlit and most of the performances are phoned-in. ** from ****