There is an outdoor aerobics class three or four times a week at two locations in Bang Saen. Not my thing (I'm ashamed to say) but it always drew a fair crowd. The Tide Resort is one venue - in front of the resort opposite the beach; the other venue is bayside close to the municipal monument. It always took place in the twilight hours. They looked very committed anyway!
There is a bowling alley on the second level at Laem Thong shopping mall. It costs 60 baht per game or 150 baht for three games.
They are open from 10am right through until 1am. It's ok to drink there and they also sell beer and whisky.
Equipment: Shoe hire is included in the price and, wonder of wonders, they cater for big feet - up to and including size 12.
There are no big waves at Bang Saen Beach. It was pretty flat and calm from what I could see.
You can rent a tire to take in the water for 10 Baht per hour. Fun for the kids I guess.
Open from dawn till dusk. The guy in charge of the tires also rented out deckchairs and sold drinks and snacks.
'Relax Bar' is a local hangout at the western end of town. It's an outdoor setup and they serve meals.
You can sit by the water and have a drink - they also have a huge screen on which major sports events are shown nightly (when I was there it was FA Cup followed by NBA basketball).
Great atmosphere - this place has the right name!
There is a great spot for jogging alongside the beach. I never tried this myself but it seemed to be popular with the fitness lovers. The paved area alongside the beach is about a kilometer long.