We don’t suppose that scrubbing a drone in saltwater is going to do much harm, particularly after it’s been retrieved from 30 feet under.
When a sailor becomes overdue in making landfall or regular radio contact, more often than not it turns out that there’s a simple explanation such as lack of wind or charging problems.
If you’re planning to sail out the Gate today, be advised that the Coast Guard 11th District has issued a warning to "vessel owners, operators, and beach-goers of high surf and winds affecting the Bay Area."