From OMAT - -

"......Initially Hilton’s website suggested that the roundtrip transfer cost $370 plus a 23.2% tax and service charge. As it turns out, that was a mistake, and the hotel is actually charging $350 one-way plus a 23.2% tax and service charge for transfers between the airport and hotel. So a roundtrip boat transfer for the 30 minute ride will cost $862.40. WOW."

OMAT - WA link