I guess I was concerned about the depth of the marina, current, and how much I need to pay attention to tides entering and leaving (6' draft) . As long as the tide is +1 ignore the ebb & flood (but SOG is faster or slower). The thought of meeting a tug and tow in that small passage scares the stuffings out of me.
Is north leaving or is that returning ??
As I wrote in my article about the "ditch", some things to consider:
1. "B" dock, where we moor our boat, has ample water. A minus 2.8 foot tide might leave our keel (five foot draft) just touching the mud bottom. Otherwise, not a problem. However, I cannot speak for other parts of the marina in relation to water at the dock/slip. There is one spot when heading out/returning from our slip and that is the waterway intersection mid way to the marina entrance where I have experienced a shallower part of the marina. To avoid getting stuck in the mud at lower than normal water (another story), I always leave/return when there is at least a plus one tide state.
2. Ditto when transiting the ditch; I always make sure that the tide state is at least a plus one to avoid getting stuck in the mud along the way. Tide currents can run two plus knots, so will try most always to leave on an out going and returning on an incoming. Neap, or short cycle tides, currents run very weak and will make little difference when you do your transit.
3. In all the years of transiting the ditch rarely have I encountered a tug pulling a raft. When so they always leave ample room to get by. In season the crabbers like to drop their pots (50-100) in the middle of the north channel causing one to dodge and weave around them. And the "no wake" zone in the channel means they can go as fast as they want. Grrr.
4. Shelter Bay places you in the Islands as opposed to spending five to six hours just to get to them from Everett. We used to be in the Everett Marina many years ago and it was the over-hang regulation that caused us to relocate; another story.