Sounds like an fun adventure even with the goofy currents. That warbonnet in the zoanthids is awesome!
Low exchange days at Skyline are weird. Kelly at Anacortes Diving told me that you want to look for exchanges at or over 1 knot to get the flow to switch. We usually get in the water about 45 min before slack on days with an ebb between 1 and 2.5 knots (and with a similar flood) and it is pretty much spot on most of the time. Full disclosure, we plan for drifting out deep in the crimson anemone zone, and then at slack we head shallower and leisurely drift back on the upper reaches checking out the zoanthid patches. I don’t bother planning for a slack period to play around in, but it happens sometimes. I’m sure Jan K or others (H20 doc?) probably have some better info since I’ve only been exploring out there infrequently for a couple years. Also I usually look at the deep zoom current station between Allen and Burrows Island (or at Green Point) to guess slack and seems to work close enough.
If anyone ever wants to go for a dive out that way then hit me up on the messaging. It’s always fun for us lonely divers up in the far north to meet the active south sound crew