I and many of my F/O's have jumpseated on Blue Hawaiian in LIH and KOA and they were great. You can call them and tell them you are a pilot with United and would like to jumpseat. They will check availablity and let you know what time you should show up. It holds 6 pax . When there is a party of 3 ( parents and child ) there often is going to be an empty seat. Enjoy