#sea_boat__seaboat  a boat that is seaworthy; that is adapted to the open seas
  supertype:  boat  a small vessel for travel on water
  subtype:  lifeboat  a strong sea boat designed to rescue people from a sinking ship
  subtype:  whaleboat  a long narrow boat designed for quick turning and use in rough seas

No statement uses or specializes sea_boat; click here to add one.