Certain figureheads have wood behind them that doesn't match the rest of the ship unless you use the default hull (most noticeable on the huntress and shark figureheads).
The default wheel, cannons, capstan, and masts will often change color to match certain hulls, but if your ship sinks, they will swap back to the default color.
If you find a chest of sorrows, you can place it on a fresh rowboat found at an island, then attach the rowboat to your ship, and the crying will not flood your boat.
