>> I was thinking of a nice clear warm Atlantic beach like near Ocean City. <<

That's possible.

>> Fury would definitely look over dressed. <<

Fortunately they aren't in public view. There are private beaches.

>> Also a young Coulson couldn't blend in with the bland and harmless as easily -- he's not middle aged and balding and in a suit. He would have to work to disguise the young, fit, and trained body, and work even harder to disguise the air of alertness and observation. He could still be a young man of average size, average shape, normal clothes, not looking particularly strange or dangerous but he would have to put some thought into it. <<

He can do it, but as you say, it'll take a little extra work until the spit-polish wears off a bit.