Hey over twards Jomtien theres a decent little amusement park they have waterslides a few rides and stuff but theres also beach access I went there this last trip it made for a fun day.. if your looking for it just head twards that big tower with a resturaunt on it thats the place its easily visible from just about anywhere its off the main road so it will cost a bit more to bring you there admissin is 100 baht
another great place (I found in part by accident) if your looking for some water fun is Mikes department store... yes thats right! Mikes Department store... go up to the top floor then walk up to the roof they have an enormous pool area up there its quiet and not crowded and when I went it wasnt too hot because it was breezy up there.. there is a spectacular view too theres deck chairs and a snack bar pool is really really big... so if your staying at the dynasty and dont feel like swiming in thier bath tub pool head over there.. downside is its 60 baht per person