Don't be so quick. I discovered a huge problem when designing a dinghy storage facility (besides the fact that my club has about 10-15x less then what would be needed).
Having the racks is nice and all, but you also have to take into consideration how you're getting the boats onto the racks. By making just two end supports, and no middle supports, it becomes a game of leverage to get the boats on. Then it's only possible with two people.
You need to determine now some design requirements.
1.) How will you put the boats on to the racks? If you put them up bow first, then you need longitudinal supports to slide the boat on. If you want to slide them in sideways, you just need cross supports AND have the entire length of the structure be longer then your longest boat.
2.) What will be placed on the supports? Are you going to have just bare wood? Or will you place carpeting, to extend the life of your boats?
3.) Will this rack be near water? If so, it'll need some sort of sub structure like concrete placed around a wood timber.
4.) Will the boats be stored upside down, so as to keep the elements from pooling? You'd be surprised how heavy those things get when they are filled with water. Plus if you don't add in space to dump it, you'll have to take it out manually, and THEN dump it.
5.) Will you build a roof over it? Even a rudimentary roof isn't entirely necessary, but it does show how manly you are.
I'll probably think of more later.
