I can't promise the water will be warm (in fact it will definitely be cold) but go here if you're dying to catch some rays or dip your toe in the ocean
Amazing, amazing food and a great atmosphere. If you're looking for something more upscale but not too stuffy definitely come here for lunch or dinner. Walk around the wharf to look at boats and do some window shopping before or after!
This walk has the most incredible views, or so I've heard... a perfect activity to do if you want to burn off the pasta, clam cakes, and milkshakes you just consumed from my previous recommendations