I saw a similar thread, but I apologize that I have never visited to Seattle and I'm still confused. We are wanting to rent a large vehicle for 6 people at the Seattle airport on 6/28. We are then spending 3 nights in Seattle before departing for a cruise to Alaska on 7/1. My confusion is where/how to return the car. It is not super clear on the sites. Trying to figure out the cheapest way to rent a car/transporting ourselves easily to port. We once paid $171 on Uber in DC for 6 people with luggage, so I'm trying to avoid another situation like that!

The question is whether you are sailing from Pier 66 or Pier 99? Pier 66 is easier. If you get a close hotel you could even walk. Port of Seattle - Search Seattle Cruise Port Hotels
Depending on what you want to see in Seattle, you might not even need a rental car. There is a good light rail system from the airport into downtown Seattle.
There is a pretty good bus system in Seattle as well.

It's not that hard, but you might not like the price.

You simply rent the vehicle from the airport and return it to a downtown location. If you want to drop most of the passengers off at the cruise terminal before returning the car, it will make it easier to take a cab from the car rental office back to the dock.

Three companies - actually the same ownership - National, Alamo and Enterprise - have a downtown office with a free shuttle to the cruise terminals. Whether they end up cheaper than using another company (and paying for the cab) is something to research. Cabs from most of downtown to Pier 66 (Norwegian and Oceania) cost around $10 plus tip; to Pier 91 (everybody else) around twice that.

The major companies have started charging expensive one-way fees for vehicles picked up at the airport and dropped off downtown. Depending on where you're staying, you might find it cheaper to take an UberSUV or two taxis when you arrive, and set up the rental from one of the downtown offices so you can return it there without the one-way fee. An UberSUV will cost around $60 to downtown from the airport; a cab will cost around $40.

Note parking at downtown hotels is very expensive. Where are you staying?

Another problem is that you're wanting to return the car on a Sunday and many non-airport car rental centers are closed or have limited hours on Sundays. Avis and Budget have locations on 5th Ave and on 4th Ave , and since you qualify for weekend rates have a van available for around $200 for the 3 days. Some of their offices offer rides within 5 miles so you might call and ask about rides to the Pier. (1) 206-448-1700 is the location on 5th.

Note that it is not that easy to fit 6 persons and 6 sets of luggage into a 7 seater van. Sometimes 2 mid-size cars with trunks work out at the same price,( though you'll have two parking charges at your hotel).

Thanks so much for all of the answered questions! This has really helped! I tried to respond yesterday and it said you could only post twice in 24 hours or something. To answer questions:

We're heading to Pier 91.
Actually staying out of town in Lynwood, since accommodations for a family of 6 right downtown was so expensive, although we would have much preferred to do so.

The info has helped tremendously. I think per advice from all you good folks we're going with Budget. Did price $ and it was about $400 to go with Enterprise with free shuttle. I called Budget offices and they said no Budget or Avis has shuttles to the pier any longer. So, our rental will be a little less than $200 for 3 days. Then we'll take the advice given above about dropping off everyone and luggage and one person returning the van. Then, that one person will Uber/taxi back down to Pier!

Thanks a bunch! You've been great!!

i would look at the price of the car, including driving and parking it downtown on visits during the day, then consider whether that makes it maybe more economical to stay downtown and nix the car.

That's a good thought too. The price to stay downtown to accommodate 6 was much more unfortunately. The rooms (or houses/apartments on Air B&B) were really pricy downtown. We would definitely spend more than the price of the car, but really didn't factor in parking which I probably should have. I know parking is $$ too! Now am trying to figure out which app is best for picking the best parking while we're there.

The best trick for downtown parking is coming in on a weekday, and getting an Early Bird Special. I can park for either $16 or $18 in Pioneer Square as long as I get myself in before 9:00 or 9:30.

Crunching the numbers - just a little - is also helpful. Bus fare is going to be $2.50 or $2.75 each way (depending on time of day) so moving six people around is going to cost $30 or $33 round trip, vs. a lot less to park, even if you're paying a couple of times. Downtown is walkable (if hilly) but your time is worth something, especially on a short visit, so I wouldn't be too quick to think that parking + public transport is particularly economic.