Any FW in the area will be brackish, don’t think you can get far enough to stay in fresh water for any length of time.
Your choices are the Duwamish River or the Snohomish River or the Fraser River.
How far can I go up with my 7.4’ draft?
There are good charts for Duwamish and Fraser rivers to show how far you can go. The Snohomish not so much. Soundings end about the confluence with Steamboat Slough. I have made it just past the bend to the east at Lowell with 7' draft. The river is tidal so watch your step.
Not far enough....you need a lake, thus Lake Union, Salmon Bay et all. The Govt. Locks, PITA but really the best option.
If you belong to a YC a lot of the clubs on the lake have reciprocal moorage.
Salmon Bay is basically the ship canal so no anchoring. We used to head over to Andrews Bay frequently. Anchoring is allowed for three days (many stay longer). Mid-week is very quiet weekends get a little “spring break-ish”. Great access to hikes and a short dingy trip to the docks at Leschi for groceries, restaurants etc.
If you belong to a YC a lot of the clubs on the lake have reciprocal moorage.
I am a member and I used to do reciprocal, but clubs are closed now.
I'll give a try to Andrews, but I can only go on weekends. I am not a big fan of party atmosphere. I'll try to find a remote enough spot there.
I'm pretty sure I've seen your boat in Eagle Harbor. Are you moored just West of the public dock?
Yes, I looked at maps and it is quite tiny/narrow channel where you can navigate. Was there any traffic to deal with? Is there space to turn around, if needed? How strong is the river flow?
6' 2" draft? Willy? LOL
If you want to go to Andrews bay on a weekend, just wait for crappy weather, which seems to appear with some regularity on weekends. I can see it from my house and the crowds are totally weather dependent. If it rains, it will be empty!
Not completely true! The lake gets lowered a few feet in the winter and raised up again in the summer. OK, that's not exactly "tides", but my slip on Lake Union isn't a floater, so I always have to be sure lines and fenders are correct for the transitions.I waited a second or two and then told him he was in fresh water now and no tides.