First, thanks to you and all the others for thier service. I started sailing on an H16 on a large pond on Indiana. Then I moved to the North Shore of Boston and sailed off the coast of Marblehead. After a few years of doing that I ended up with an H18. I moved to Annapolis a year later and sailed it near downtown. Both the H18 and H16 have thier strong points. After sailing the H18 for a few years I found myself wanting the H16 again. The H18 is great for two people. You can really squeeze every ounce of performance out of it. I found that without mast up storage I did not sail it very much. And yes, you will need another person or righting assistance if you capsize. I was about 250 when I had the H18. It is a great boat. That said I prefer the H16 for my sailing preferences.
They are still quite fast, you can launch the boat from a trailer to the water in 15 minutes solo, I find it easier to keep a hull up, if you can capsize the boat you can right it solo if you weigh 200lbs or more, I have no qualms about running it up onto a beach, and I find the sail to be a bit more dry. There are also more racing fleet for the H16.
It is much easier to tack the H18 without backwinding, especially with crew. The dagger boards allow this. The H16 almost always has to be backwinded when solo, and many times with crew, since you have to drag the assymetic hulls through the water. Just move your weight as far forward as possible when tacking.
Get Catamran Sailing: From Start to Finish by Berman
. This book will greatly steepen your learning curve. It takes about an hour or two to read cover to cover. I read it every spring and always seemed to learn something new.
I used to be pretty active on the Hobie board under the alias of HobieNick. If you have any questions about either boat, let me know. The wife and I started a family last year so she made me get a bigger boat. I can't wait until my daughter is old enough to start sailing the H16.
Have fun and keep us posted.
Sick From Prilosec