shark ID

[JOHN D]

I know its not nj, but yesterday I was fluking in in the back of Gardiners bay in long Island, where at least i thought sharks don't really go but now I guess not. I caught a sea robin and stripped it up for bait and threw the carcass in the water and about a minute later, a shark, about 4 ft started hanging around my boat all day (probably because I was feeding it my bi catch of live sea robin and porgys ) but the really strange thing is that it was in 20 ft of water in a bay. people told me it was most likely a sand shark, but ive caught hundreds of those things and it was no sand shark, It was much more sporty looking. I tried to take a picture but the glare made it hard. I know the information is vague, but does anybody know what it could be.