Where are they getting married? Maine beach wedding would be so much different from one on the islands. Are you looking for something tropical? How big? Cutesy, themed or more mature? Would it go on their bed or wall or throw for living room?
Baby Honu... Has turtles and pp'ing for waves. Just Crabby had pping for waves and crabs.
When I think of Maine, I think of darker blue for water and it makes me think of storm at sea pattern. When I think of Hawaii, I think of the Baby Honu pattern. The tropical islands makes me think of turquoise and blue and lots of different blocks with applique like palm trees, hammocks, islands, pina coladas etc.
Hope that helps a bit...