In my time as a youth sailor (a few years ago)I tried to raise money tons of times and was very unsuccessful. Unfortunatley many companies don't want to give monetary hand outs. If anything I would suggest putting together a little resume and going to small local stores, especially ones where you know the owners are sailors and asking for small amounts of money say around $100.
The North American Hobie class also has a youth grant program... check it out on HCA-NA.org under youth sailing. Some divisions and fleets also have money they can have set aside to give youth sailors. All this happened after I aged out! So I was totally on my own but you should def. try to take advantage of it.
Bob Merrick, recently appointed HCA-NA class president was one of the coaches at this seminar last year, if it's the same one i'm thinking of. I would try to email him and ask him if he has any ideas, he is a huge promoter of youth sailing and will do anything he possibly can to help you out.