Gates Green Stripe Belts come highly recommended from just about every source I can locate. Since I couldn't find *any* negative comments about them I decided to go with the winds of wisdom. Unfortunately, Gates doesn't make a belt small enough for the water pump, and the technician at the store was concerned that the green strip belts did not have as high a sidewall as my original. That means it may not have the proper "bite" on the pulleys.
The next thing I did probably should have been the first. I went to the CS Owners Association Yahoo Group and did some digging there. Turns out that somewhere around page 4 of the search results I came on this:
> The Yanmar part numbers are 104214-42780 (water pump). Not bad at $6.30!
> and 104211-42780 (alternator). Again, priced at $6.30.
> You can order from www.marinedieseldirect.com
Ahh ha! Saved by CSOA yet again. Seriously, if you have a CS Yacht and haven't joined this group you need to.
In the interim I picked up a new Gates XL 7290 alternator belt. My new plan will be to order the correct Yanmar belts from the web site above if my local marina doesn't have them in stock. I'm amazed that these Yanmar parts are reasonably priced. I would have expected a hefty marine tax on them. Certainly makes it an easy decision to have a few spares around.