You could almost pick anywhere on the coast between Felixstowe and Lowestoft and have a good time shooting minimalist seascapes at anytime of the day so lighting isn't too much of an issue if the weather isn't great. Aldeburgh, Southwold, Walberswick, Woodbridge are all good locations. We were there for our summer holiday last year and really enjoyed our time there. Have a look at my flickr photostream for a few ideas if it helps.