Hmm, that'd be about $357 worth of laundry for the cruise if we did the $7 per day. Guess we will just send in the occasional bag of laundry and do some in the cabin as well. So, I should buy some soap in Seattle before we get on the ship. Guess I'll get the clothespins then, too. I should make a list of all the little stuff to get before we get on the ship. Laundry soap, clothespins, suntan lotion, sunburn creme, etc, the basic little stuff that lives in the medicine cabinet that would be ferociously expensive to buy onboard. Some of our ports would have shops with that sort of things. On this itinerary, it looks like some of them won't.
Kona is in the lee of the island and it's almost always calm on that side so it shouldn't be a bad tender port at all. It comes into a dock once it gets into Kona, right where they start the swimming part of the Ironman triathlon. So, should be easy enough to bring another suitcase. It would save on a checked bag from Hawaii to Seattle which runs about $50 these days, I think.
For the Kona port, once you get off the tender, you're literally right in the middle of town and Kailua-Kona is the tourist town on the island. Should be a really easy port to just wander around and not have to have an excursion. Honolulu is the same way, although there the cruise ship is at a dock so it's even easier.