4 days is quite short. Too short to learn to dive but you could go down to Pattaya to catch some sun or in my opinion a better 2 days spent in kanchanaburi. There it is peaceful and quiet and you can do some jungle trekking, float down the river kwai(literally on a rubber tubing), sit under some waterfalls etc. Away from people and the bustling city for a change.Why not? Enjoy
down the river kwai
waterfall
