PENATRATOR PENATRATOR:
I remember when I was a small kid living in Victoria, my Dad and I went down to the marina in Pedder Bay to his boat only to fine it had been taken over by a family of these otters, what a mess!! The people from Sealand came and took them to their park.
Are you sure you're not thinking of sea lions, as it is extremely rare for sea otters to ever come ashore especially onto a boat.