Join the GPS Teams Challenge. That way you can actually measure your windsurfing performance besides doing freestyle and waves. Getting and beating PBs helps motivation. For example I've achieved a fair few PBs this summer. Its great getting a PB and its motivates me to windsurf more and better.

However it could be a two edged sword in that without the GPS it may feel like not being worthwhile to windsurf. On the other hand I still love sailing in light winds on the big learner board and trying tricks and stuff like that.