Shotchas said..
Search under cars bikes and boats with nothing in the main search bar.
Then select "boats" in the categories,
Then select "sailboats"
easy peasy!
No, not easy peasy at all, you have missed the point of Ramona's and Cisco's posts. Your search method will find all the sailboats that are CORRECTLY placed in the SAILBOAT section, Ramona's original post was about finding boats that had been placed in the WRONG section but were still for sale in eBay as a whole eg. putting a sailboat into the motorboat section, it's there, but you won't find it with your search method.