Will it float in water? If it will and it isn't too far above the water
level of the nearby creek (15 yards? you said) dig around the boat and
fill the cavity with enough water to float it. A portable genset and a
sump pump you can probably rent for $30 or so a day can be used to pump
water from the creek to the hole. Once the boat is floating in the hole
cut a channel just deep and wide enough to float it to the creek.
Depending on the elevation difference it shouldn't be too difficult. A
hard working teenager might come in handy.
Good luck.