Pia...having been on PG twice, my number one recommendation would be to go out there at least a day early if possible. It is awesome to sleep off the flight and get up the next morning, walk or sit by the pool and get to the ship early. Both times we were able to board the ship around 2pm on Saturday while the other passengers were in the air, barely to Hawaii. By the time most passengers get to the ship, maybe 730-8pm or so, they are pretty tired.
The raft idea is great too, especially for Monday the Motu day.
Upgrade to business class at LAX is a pretty cool deal as well.