We use to do the mass lawn maintenance routine in high school to raise money collectively.
You advertise that you will deliver / spread manure, till flower beds, mow lawns, deliver rock/gravel/lumber/wood, dig holes, plant shrubs, weed as a group. Do anything a little cheaper than your local landscape artist is going to charge big bucks for and give them a receipt for a little charity donation. It is a high school club, right? And it is going for the collective, right?
That and negotiate a deal for the charter. Clean and wax the boat maybe?