Snorkelling is awesome fun when its flat, recently bought myself a new mask and shes a pearler
Also just chucking on my BB fins and going for a swim in the ocean is a good way to keep the muscles/fitness going.
Photography is a great way to pass the time and is very rewarding to after hours of shooting and coming home to froth on your glory shots.
I generally do those things to keep me busy but also get on the skatey and pushy every now and then when im not in a "lazy mood".
What i would absolutely love and have had many thoughts about opening my own is a "Flow-rider" like the one in Dubai at wild wadi, thats got to be the best way to pass time when the waves are non-existent.
Id love to get one made and open a place for it and hold comps and shit kinda like a skate park but for boogers/surfers.