Last year I noticed that one of my friends had written his phone number on his board, and that seemed like a good idea so I did likewise. Never thought about it again.
I was kiting in the late afternoon a couple of weeks ago (low sun angle), crashed after a big jump, and my board came off. My kite also crashed. The bottom of my board is about the same color as the water, and the fins are gray. The wind was a little light, and with the baggy-top drysuit and PFD I had a lot of trouble getting my kite back up in the air. I was dragged about 200 yards downwind before I got the kite relaunched. When I started looking for my board I couldn't see it. I bodydragged upwind, back and forth for probably 15 minutes looking for my board. Never found it. Dragged back to the beach, dropped the kite, climbed up into a lifeguard stand (no guards on duty), and still couldn't see it. The only other kiter on the beach was giving a beach lesson. When he saw me come in without my board, he grabbed his and headed out to look for mine. He looked for at least a half-hour, and never found it. I looked for about an hour and a half and never saw it. I walked about 1.5 miles downwind/downcurrent in my search, which was as far as I could go (shoreline blocked by a large water treatment plant). I was bummed.
Four days later I got a call from a guy who had found my board where it had washed up on the beach in front of his house. The guy lived 35 miles from where I had lost my board! When I picked it up from him (after handing him a really nice bottle of wine), I was awed by the fact that there wasn't a scratch on it, and the phone number was still very legible. All I had used was a Sharpie marker to write it on the board. It took 30 seconds to put my phone number on the board, and it saved my $500 board.
Don