Well, if all you need is
Log speed and distance data, then the Mini Motion is unbeatable and significantly than those $$$.
But if you want a screen to view results while you are active, that is a different problem.
The Home Built GPS's ESP is probably what you are looking for but you either have to build it yourself or get in a group if friends who do a group build. Both options require at least some basic skills and tools.
see this thread:
www.seabreeze.com.au/forums/Windsurfing/Gps/Another-DIY-GPS-logger-approach?Many people are buying a Mini Motion and a more inexpensive Garmin Sports watch for in the water feedback on used for other activities, especially with the Garmin GPSTC Datafield that Andrew Haigh has developed and generously distributes free of charge. This great app gives you all the info you could want for most sailing things.

see this thread:
www.seabreeze.com.au/forums/Windsurfing/Gps/Garmin-GPSTC-Datafield-to-complement-the-Motion-Simple-Logger?page=1