da_marlboro_man, nice job answering your own question.
Take a drag off this instead.
A friend had a tandem in S.D. (he had to go to P.R. to get it) that we took out on Rio Cumayasa and Rio Chavon - and into the ocean.
So first off I'd tell you to bring one with you, if at all possible. Figure on paying one-way shipping (take it with you on the plane) keep it in good condition and you may get your original investment back when you depart, perhaps more. Someone on the island will (should) want it. They keep their value, as long as you're not wearing cowboy boots, smoking red's and ........
The Chavon River is easy to find, but it's a haul from S.D. Mostly highway, I forget exactly but figure close to 2 hours.
Cumayasa is relatively easy to find, far more remote and even a bit (maybe a lot) shady. It's probably 30 minutes past San Pedro de Macoris, so figure an 1.5 hr. from S.D.
Upriver, one side is mostly mangroves filled with birds, the other is mostly homes and private docks filled with some outrageous boats. We didn't go all that far upriver before heading out to the ocean. But it looked interesting, if not inviting.
Closer to the ocean it's like you see below on the east side; mostly coral platforms until you run into a resort. No fish to be found this day.
<img src="http://xs18.xs.to/pics/05093/gliding3.jpg" title="East side is all mangroves, birds and high coral platforms">
The West side, where you drop in has easy access. That colmado in the distance is about the only landmark I can offer, and the CuttySark of course.
You'll likely run into the owner of the CuttySark, he'll prove useful for your storage needs if you find this to be a good place. Can't remember his name, but he may be lurking here on DR1.
Once you get out into the ocean you can see Catalina Island in the distance?a doable trip if you've got some stamina, a 12 pack......and a boat to tow you.
These guys in the distance were on their way to Catalina so we asked for a tow, we yelled "throw us a rope". They threw us a rope?the whole damn thing.
I just remembered the Isabella too, in S.D. There's a marina that you can store you boat at as well. There may be some pollution, but nothing like the Ozama, just go upriver.
If you see this guy near the marina, tell him I want my sheet back.
Seriously, if you go west, I think you'll do fine. Las Salinas I bet would be great, some tremendous vistas, especially on a sunrise paddle, there are some huge mtns. that face East and probably are lit up like they're on fire at sun-up.
The bay beyond Palmar de Ocoa is an awesome spot as well, with easy drop-ins. The best water I've seen anywhere on the island.
Also, are the caves and lagoons in Los Haitises Park. That would be killer.
I think it's an untapped resource of fun for the island. You get to explore the rest and report back.
It's a whole different view when you're that close to the water.
Good luck.