Look over in Trainboard on "ATSF Line Started", that's Jerry's thread, and I think he's set new standards for waterfront trackside modeling; he's doing SP on the San Francisco Bay but it's quite remarkable.
I think what make's Jerry's special is how much space he spent on WATER. I've seen guys do a couple inches to infer it is seacoast or whatever, Jerrys' probably consumed about 1/3 of the horizontal distance just on waves. I've never anything else like it. When he shoots shots over the water, or a distant shot of a long train, he's got enough water to make it convincing. That's the lesson I pick up from it.
Another one of those things the HO guys can't do at all unless they have a gymnasium to work in.
I'd definietly opt for one of the locations that has something vertical rising behind the trains. Nothing against Florida East Coast, but flat is flat. You need something big behind it.
CA coast; ATSF Surf line down to San Diego. SP up around Santa Barbera. Santa Cruz has fantastic cliffs with trestles, unbelievable.
Even the NWP has a nice location or two up in Humboldt Co. just before Eureka, with coastal redwoods on the skyline.
Tacoma has some nice waterfront running with the City behind it, and both north and south from Seattle has some impressive bayfront running.
East coast; check out Maine. The Calais branch is rather legendary, Rockland branch still running passenger.
I'm not sure you can do 'generic' seacoast though convincingly. The geography will instantly tell people where you are if you do it right. You can fudge on the railroad name more than the scenery!
http://www.r2parks.net/MECmap.JPGYou'll sometimes find your favorite railroad in some of the darndest places. I have a favorite side shot of N&W 611 perched right on the shore of Lake Erie, looks like on the Atlantic coast, right on the ex-NKP main line. Check out the location on Google Earth, right between Lorain and Vermillion. Your 'backdrop' is the enormous Ford plant there. Nobody models that, no idea why. Heck, you can even put UP out over Great Salt Lake if you want waterfront modeling!
I'd never ridden down the Hudson on NYC until two years ago. The railroad darn near has its feet wet on the east side, and most of it has a pretty decent cliff behind it much of the way. If it's not 'seacoast', what is that container ship doing out there? The West Shore is a little higher, but not by very much, and scenes like Bear Mountain have been done in N as well.
