- nice wide band you can wear on your upper arm
- large digits that can be read even while sailing
- durable - after 13 years of light use it started acting a little strange last year (not responding to "mode" button), but with some cleaning, that issue seems to have gone away.
BWD uses one that displays a wave count.
Given the high number he gets, he needs it - me, on most days I can count my waves on the fingers on one hand.
This one is interesting too - plots your rides (Garmin likely does this too)
http://www.ripcurl.com/searchgps-1.html