Couldnt finish GHG when I played it in the 80s but knew I needed to get into the ship. Never found an entrance but did find a loop hole. If you dropped the Holy Grenade in the ship room and left - the explosion would create openings in the water blocks. You could diagonally move through water blocks - after enough tries I was able to touch the gang plank or door on the ship to enter allowing me to finish the game.
- 6BQ5 likes this