First off sorry there's no pictures. It is hard to spot good stuff from above the water and even when one does it will be hard to photograph. From the boat and shore most of the time I only saw the common jellyfish anyway.
I figure this isn't going to be combined with the adjacent Gwaii Haanas NP due to it being mixed culture/nature focus rather than just marine biology. We are talking about a large area between the park and the lower mainland that is considered. The waters here are quite shallow and having brought in the minerals from the ocean the hotspot here thrives. Even the ferry across has to take a specific route to have deep waters to get through.
So while I barely touched the surface (no pun intended) and a dive would be better to discover the marine life, the cold water doesn't make it very attractive. Some people went skinny dipping in this weather back at the lodge so a 7mm wetsuit may just be enough to survive an hour underwater, though I think arranging the dive itself is a biggest issue. I'll give it thumbs up as the marine area here is generally wonderful although which part it will eventually include is undecided. The strait is quite large and touches the park areas too.