- Irc -
- - Ironclad.
- IrcFltBtry -
- - Ironclad Floating Battery.
- IrcGbt -
- - Ironclad Gunboat.
- IrcRam -
- - Ironclad Ram.
- IrcSlp -
- - Ironclad Sloop.
- IrcStr -
- - Ironclad Steamer.
- IrcStFltBtry -
- - Ironclad Steam Floating Battery.
- ScFr -
- - Screw Frigate.
- ScGbt -
- - Screw Gunboat.
- Sch -
- - Schooner.
- SchBg -
- - Schooner Barge.
- ScSlp -
- - Screw Sloop-of-War.
- SL -
- - Ship-of-the-Line.
- Slp -
- - Sloop
- SlpW -
- - Sloop-of-War.
- SlvBg -
- - Salvage Barge.
- StBrig -
- - Steam Brig.
- StFr. -
- - Steam Frigate.
- StRam -
- - Steam Ram.
- StTBt -
- - Steam Torpedo Boat.
- StwGbt -
- - Stern Wheel gunboat.
- StwRam -
- - Stern Wheel Ram.
- SwGbt -
- - Side Wheel Gunboat.
- SwRam -
- - Side Wheel Ram.