nonsinkable
adjective
non·sink·able ˌnän-ˈsiŋ-kə-bəl 
: incapable of being sunk : unsinkable
… whale boats molded of glass and teflon and made nonsinkable by plastic foam in all dead spaces.
Robert A. Heinlein
Robert A. Heinleinnonsinkable vessels
Word History
First Known Use
1875, in the meaning defined above
- flash bomb
- flash burn
- flash card
- flash color
- flash defilade
- flash drive
- flash factor
- flash flood
- flash forward
- flash freeze
- flash freezes
- flash freezing
- flash froze
- flash frozen
- flash grenade
- flash grenades
- flash hider
- flash hole
- flash in
- flash in the pan
- flash mob
- flash paper
- flash pasteurization
- flash photography
- flash photolysis