I fished the same areas littlefish just mentioned. The larger fish that came in were mostly caught out at the light house, they were only a few pounds heavier. Plus staying inside was a lot less crowded. A 17' would be fine but you may have to move around and find a sheltered bay if the wind kicks up. If you put in at Gold river you may have to adjust to the weather. Last year we had great weather but the wind nailed us on our way back.
My favorite spot for the morning bite was just west of critter and then Hois point for the nooner. Catching kings like silvers at sekiu in september.
I did hear about the shrimping in nootka and as a result I bought a pot puller at the sportsman show.
At critter cove they will post daily catches and weights on there web site. Check it out!
And by the way... If you are headed to the island you should reserve your ferry trip now!!!! Go to BC Ferrys and book it. My preferred boat in July was already booked full.
Hope this helps.