Once you have finished your scuba diving course you can relax at one of the many great beaches: Aow Leuk, Tanote Bay, Freedom beach or Jansom beach. All offer azure blue waters great for swimming or snorkeling; beautiful surroundings and a place or two to eat or drink and relax.
Need something more adventurous? Goodtime Thailand offer rock climbing, abseiling, bouldering, hiking and more. They are easy to find on Sairee beach.
If you have energy to burn why not practice yoga at Grounded or work up a sweat at the Muay Thai Training Gym; they have regular fight nights each month where you can watch several fights of different weight categories, it makes for a great night out. Fancy a workout? Then try Gym and Fitness they have day, weekly or monthly passes.