I was in Bali just last month. Apparently Blue Oasis at Sanur is the only windsurfing rental place around on Bali. But the gear there is quite old and limited as you can see below. The water there is rather shallow too for quite a distance…with tons of water plants & corals. Only saw 2 people trying windsurf…1 was a japanese guy who was pushing his own gear out. He seemed to be walking on & on forever.
A friend of mine was kite-surfing there and got dragged by his kite, resulting in cuts all over from the corals...looked as if Wolverine attacked him. So do be careful.