Hi , I live in Crofton and launch just down the road from my house( been in Crofton for 38 years) there was excellent winter spring fishing many moons ago before the runs in the area got slaughtered, off the cliff face at Tent Isl. was quite productive at depths around 110 ft, small minnow herring and anchovy worked well, so did strip in a clear head with the narrow red stripe on it, hootchies were also good mostly in the green colours and army truck patterns.
As for the prawns look on your area map and find the deep holes directly out from the cliff face of Tent Isl. , you will see 200 ft depths and then several holes to 265 ft to 300 ft, thats the spots on the ebbing tides, for some reason they are scarce on the flood even though it's only 1/4 knot faster according to the charts, I thought at one time the tide height(volume of water moving) made a difference but in my experience it has not.
Porlier Pass is much the same, fish the outside on the flooding tide around the bell bouy or down to half moon bay anywhere from 55 ft to 165 ft as the bottom drops off, the commercial guys years ago followed the 30 fathom line and trolled at 100 to 145 ft for the springs.
At Porlier watch out for a NW wind that can come up quickly, running the pass on a hard flooding tide and a stiff Nor'wester is ugly , stay close to the South side and watch for haystack boiling waves they will throw a lot of bubbles into the prop and cavitate the poop out of you especially in a smaller boat with low freeboard.
AL .