Answer: FIN

AnswerCrossword Clue
FINFive-dollar bill
FIN"Jaws" sighting
FINFive-dollar bill, in slang
FINSturgeon steerer
FINShark "trademark"
FINFive-dollar bill, slangily
FINBad thing for a surfer to see
FINFeature of some late '50s cars
FINDorsal appendage
FINVertical stabilizer
FINIt may be dorsal
FINOld El Dorado feature
FINFlying fish's "wing"
FINFlipper's flipper
FINShark ... soup
FINYacht appendage
FINAquatic appendage
FINOminous sighting in "Jaws"
FINPickerel propeller
FINAlbacore appendage
finto equip with paddle like structures
FINTorpedo feature
FINShark's appendage
FIN'59 Caddy adornment
FINFiver
FINFeature of 50's autos
FINShark sighting, often
FINA shark's scares you in the water
FINHalf a sawbuck
FINSemisawbuck
FIN'50s car feature
FIN60's car appendage
FINHull projection
FINFish's steering mechanism
FINFive-spot
FIN"Jaws" omen
FINBygone auto ornament
FINFlipper
FINSnorkeling accessory
FINRocket feature