Everything munkispank said...
Plaza is the only one of the three with any sort of beach. But there's not really any shorediving there though - I think they teach classes off the beach, but it's not a listed dive site. The main Toucan diveshop is on-site for boat diving or you can pickup tanks 24/7 and go shoredive. Plaza is much more of a resort first and a dive resort second, the others are definitely dive resorts. I'd guess Plaza was slightly newer than the other two, it looked like the nicest of the three also.
The main difference on Bonaire is that most of the dive resorts are pretty much north of town one right after the other, perched on cliffs/rocky areas right off very diveable reefs, whereas Plaza is south in a low, sandy area with no immediate offshore diving. If you're looking into Buddy's I'd inquire about Lions Dive also, it's right next door to and I heard now owned by Buddy so you share their facilities but it's a little nicer - probably a little pricier too. To the best of my knowledge, none of the northern resorts have much of a beach - not that there's alot of beach anywhere on Bonaire. Plaza makes theirs.
Plaza is closest to the airport/flightpath if that kind of thing matters. The Port Bonaire condos on their property are under the flightpath, the resort itself is a little farther north so it's not such a problem. There's not a lot of flights though, especially since DCA shutdown.
Personally (never having stayed at any of them) I would pick Plaza, Buddy's then Capt. Don's. Especially for my honeymoon. The only advantage to staying at the dive resorts is to dive on-site there. Cliff at Capt. Don's is worth diving, it's a great site.
Regarding Belmar, since waterboy72 was there, the diveshop was taken over by Buddy's so if you were to do any boat diving with them, you'd have to drive 15min. to Buddy's. Food's pretty pricey on Bonaire, so factor that into your decision. Plus do you really want to cook on your honeymoon?
What we found was that pretty much wherever we dove, we were never more than 1/2 hr. away from our condo. It would be the same with any of the three places you're considering, they're all on/near the main road on Bonaire. The only limiting factor on Bonaire was how many tanks you could carry. All of the resorts have drive-up tank pickup. All of the really good divesites are 5-15 minutes further north or south from any of the resorts, so it doesn't appreciably matter where you stay when you have a truck.
Have a great honeymoon.
