I read with interest the story regarding Sea Lions invading the marina.
SUGGESTION: try to find someone with a couple of trained border collie dogs and have them come to the marina and set the dogs loose on the Sea lions. They are the GREATEST herding dog on earth and will obey commands like you would not believe. If it works the buy a couple of pups and have a trainer train them to put the run on the sea lions.
I will be amazed if you come back to me telling me it didn't work. One other thing is I think you would find that most of the boat owners would make friends with the dogs and make them their pets.
Good Luck
Don Harrison
1137 Stillin Drive
Ladysmith British Columbia
Canada V9G 1P2
250-245-2254