I was told it's against banking regs in NJ, so it may vary state to state. Here you have to either take an equity loan against your house, or a loan against your boat - assuming it's worth more than the slip.
95 Catalina 30 Island Time
“The sail, the play of its pulse so like our own lives: so thin and yet so full of life, so noiseless when it labors hardest, so noisy and impatient when least effective." - Henry David Thoreau