It is fairly standard for lifeboats to be self-righting. Google "self-righting boat" for examples. The typical shape is not a gömböc, though. A gömböc would self-right, even when completely under water.
The self righting designs I'm familiar with for (large) dinghies have a lot of lead in the bottom of the boat combined with a lot of built in buoyancy - they'd probably self right deep underwater.
I'm sure a gomboc would self-right when completely underwater, but what about a floating gomboc half-submerged? Different problem.
Also, ships are not solid (as in 'filled'), let alone uniform in density. On top of that, hydrodynamics imposes more important constraints on shape. You can make a ship pretty stable by loading its keel heavily.