Not quite
You can use the name of just about anything as long as you don't do something that puts the corporation in a bad standing with the general public. Now, if you take a hull, put a motor in it and try to open a new business and give it a name with "Sea-Doo" in it, then you'd be sued for logo infringment or violation of a patent.
I'm sure Sea-Doo is well aware of the different organizations out here that use their namesake, generally for the good. And I'll bet you that if anyone does anything other than good, they'll have their lawyers draw up a court order to cease using the name/logo in all forms.
Oh, and we, the members of the Seadoo forum own this site. It's managed by only a few and what little is generated in the way of the premium memberhip is re-directed right back into the site. That's what allows us to grow. I know we have recently added more memory to our server to handle all the expansion the site has been doing in the past year and there are some other goodies being explored that will be forthcoming at a later date (I won't be the one to do spoilers.)