The clothing option depends a lot on what climate you are used to. If 65 degrees is not cold to you, then perhaps no jacket and bring the shorts. I see this often in California during winter when the "snow birds" from the north are here in shorts and we are in our winter wear. They tell me that they come from very cold areas and 65 is very comfortable to them, but I am cold.
We are from Southern California and we consider Alaska cool to cold for us, so we prepare with sweaters, long sleeve shirts and a jacket for back up. Of course the evenings will be colder and there is always a chance of warmer days, so think about layers of clothing to adjust up or down.
Also, be ready for the rain and the mosquitos.
We will be on the Diamond Princess after you, with our cool weather attire.
Have a great trip.