The HAWKs have been putting on land battles under the banner Armies for Kids for several years. We run a game at Historicon and then when it is over, the kids (under 10 years old) take home fully painted armies, rules, dice, tape measures, and often some terrain pieces to play the game at home with their buddies. This year, in addition to a Franco Prussian war 15mm project, we also put together a naval project.
Using dollar store wooden sailing ship kits each kid will be issued two assembled and painted boats. They will then select from a stack of sails to personalize and attach to the masts. When the game is over, they will take home a box with the rules, dice, measuring sticks, their two boats, plus two more to decorate at home.
If you want to try out the rules, they are posted here: http://www.bucksurdu.com/Personal/documents/MilkAndCookiesNavalRules_v1.pdf