Ok - here's a few questions about a (hypothetical) situation where you have a major sponsor for a catamaran race, who wants his logo on the sails of participating boats...
1. Is this an existing practice (for the catsailing world), to require race participants to display a sponsor logo?
2. How do people feel about this? Would you prefer the sticker on the hull or on the sail?
3. Technically, what type of sticker material would you use? If should obviously stick during the race but it should also be easily removed...
4. Anyone can recommend any manufacturers (I saw in another post that Robi has the printing equipment...correct Robi?)
Thanks,
Thomas
For the major distance races that have an event sponsor, seems like the sponsor logo or name is always big and on the the forward half of the hulls. It's the best place for maximum exposure in photos and videos.
Team sponsors are usually on the sails.
Why not have the sponsor supply sails for everyone? 
-Rob V.
Nacra 5.2
Panama City
The graphics are just as easily removed from sails as hulls - however, you'll find that the different sail materials might present different challenges in adhering vinyl. Secondly, people tend to get a little more sensitive about sticking things to their sails. The quality of the vinyl plays a big part in how cleanly the vinyl removes...time that the graphic remains on the hull plays largely in the equation as well. I also have a vinyl graphics business and Bonnie and I have been designing, making, and applying hull and sail graphics for several years.
Jake,
I've suggested to my wife that for Christmas she could get us name graphics for the side of our Nacra 5.5sl if we can do it for a reasonable price. A while back someone posted Boat U.S. graphics page but I'd rather not go that route. I'd rather do business with other cat sailors. How do you want to do this? Via pm? Greg
Greg,
PM please.
(sorry - I didn't mean to advertise).
Jake, I hope nobody would take offense at you putting in a plug once in a while. It hardly comes accross as advertising! Your presence here has probably been one of the most helpfull, if not the most helpfull of all since I've been reading the posts.I think most of us are indebted to you for all the wealth help you've given. Don't mean to highjack the thread, but am very grateful. Brian
Yes, Jake is indeed a very professional person to deal with. I have asked him lots of graphic questions via PM. Always there to answer.
Jake already summed it all up regarding graphics on sails and hulls.
I have learned, the higher the quality of the vinyl, the harder it is to remove.
Im a newb in the graphics business, I deal mostly with the automotive and drag racing scene. It is fun nonetheless.
Word.
Greg
Sometimes yes sometimes no. I've found that if the application is going to be on a mylar sail that while it takes a little more time to remove a premium vinyl, it comes up clean with very very little adhesive left behind. An intermediate vinyl, while thicker, leaves a bunch of adhesive on the sail to be cleaned up after you've removed the color. As far as hulls, the intermediate vinyls will remove relatively cleanly if they are not in place for a long time.
You can require participants to add a sticker of a major sponsor to thier boat. They are almost always on supplied boats at big events. In a BYOB event the organizers can word the NOR so the sailors must put on the sticker to race.
Most normal people won't complain when they find out a major sponsor has given the event a substantial amount of money to help run the event. Having the sponsor buy sails or things like that doesn't do the event any good when you have to pay the bills.
just as a personal preference, I would like to have the stickers put on the hull.
Vinyl is easiest to remove with a razor blade, and given the two options, I'd prefer to remove it from the hull in that fashion and not the sail 
Tad, You use a razor blade to remove vinyl off the gelcoat? 
I use a razor blade to remove the hair off my face (when I feel like it, or the woman deems it required), it does a fine job on stickers You just have to get them started, then you can just pull em off like a pullcord on a lawnmower!
I can sand out a scratch in the gelcoat, I have to take a cut sail to a sailmaker. 
I used a huge eraser looking drill bit to remove very old, very cheap, registration stickers off my gelcoat and it is the only shiney spot on my boat. No damage whatsoever.
-Rob V.
Nacra 5.2
Panama City
A hair drier or heat gun (if your careful) works well for removing. Softens the adhesive and the vinyl making it easier to peel off. If it's really bad take a wooden paint mixing stick. 45 degree the end and use it to scrape while applying heat.
Obviously this is not for sails. 
Hair dryer is the way to do it on hulls
When we worked on hot rods my Dad would scare the hell out of me using solvents to remove unwanted stuff from very nice, and expensive, surfaces. Buy the time I was done cringing and groaning he was always finished with the job. Acetone works well for the left over adhesive.
thanks guys....so what I hear is:
+ put the stickers on the front of the hull - not on the sail
+ have a few hairdryers handy after the race 😉
+ have razor blades ready
+ have aceton ready
+ and I would add: put all of the above away before opening the keg after the race
Tad, You use a razor blade to remove vinyl off the gelcoat? Done it myself heeps of times. As somebody else mentioned, some gentle heat from a hair dryer also helps. The sharper the razor, the easier it is to remove the offending sticker without scratching the boat.
Michael
Be very very carefull if you are going to put a razor blade against your hull. It will work well for really old crusty graphics if you only try to remove the top vinyl layer on the first go leaving the crusty adhesive underneath. Then apply an acetone soaked rag overtop of the adhesive and leave there for a few minutes (it's useful to place it ahead on the next area you will be working on). Then take the razor blade and lightly scrape away the adhesive - it will come up like butter. Beware that when the acetone evaporates (which happens quickly) the adhesive will go back to a nasty gummy state...so clean your razorblade very often on a paper towel and use many towels. If you try and rub away the adhesive left on the hull, it will smear and dry and smear and dry and smear and dry and will be very difficult to get it all removed in one sitting.
I would not recommend trying to remove everything on old crusty vinyl in one pass or even touch newer graphics with a razor blade. The new graphics - especially if using a premium grade vinyl, will remove cleanly by picking a corner with your fingernail (or using a hard plastic scraper that can be found at a local hardware store) and peeling away. Premium vinyl will tend to tear and come away in strips but will come up cleanly. Intermediate grade vinyl will come up in slightly larger pieces but will leave a good deal of adhesive behind. Waxing the hull prior to application (with a synthetic wax like Nufinish) will aid in clean removal of the grahpic and not adversley afect it's adhesion to the hull...although I do recommend doing a test before letting everyone wax their hulls first.
I recommend doing your sailors a second favor and supplying the graphics all on one solid piece of high grade white vinyl. They can either be printed on the white vinyl or built up in colored vinyl layers (using the intermediate grade now to save a little $$). This way, at the end of the event, the sailor only needs to peel away the single layer of white vinyl and all the graphics come up with it cleanly.