When I was a kid, I spent all of my free time in the Pender Harbor area. Most of that time was spent fishing the chuck, but I did put in quite a few hours on some of the local lakes as well. In the summer, Katherine lake is full of swimmers. Hotel Lake definitely has some fish in it, but they are hard to catch from a boat, and even harder from shore... but the hotel used to rent boats. I only fished Garden Bay lake once, with no success. I always had luck at trout lake. I was shore bound, but if you have a float tube or a small boat you should be able to do fairly well. I was just new to flyfishing in those days, and all I did was cast an Adams Irresistible dry fly, and wait for the rise. As far as equipment for this lake, and this area goes, I would definitely suggest a light fly fishing rig. A few Adams or tom thumbs as dry flies, a few leech patterns, and some muddler minnows should be all you need to catch trout up there.
If you have a chance to fish from shore or from a dock in the ocean up there, there is some great sea run cutthroat action to be had. My grandparents had a dock in Gunboat Bay, and I used to catch a lot of big cutties in there (I can't speak for the rest of the area though). Spinners or sparkly minnow flies always produced. I sometimes found these fish to be tentative, with two or three chasing and nipping at my offering. If this is happening, change the speed of your retrieve, and if that doesn't work, change your lure. If you fish from a dock, try casting towards the docks on either side of you, or casting up towards the shore and reeling back towards the deeper water. I never had as much luck casting out into the deep water... although that did seem to produce bigger fish. If you want to fish Gunboat Bay, there is a rough boat launch at the end of Narrows Road that will give you access to the beach. There is no room to walk the beach at high tide, but but if it's out at all you can walk under the private walkways and fish the beach for a long way in either direction; fishing is best on a rising tide. I also targeted these fish from a boat, fishing different areas of the bay, and all I can really say about that is: explore. They sold their place a few years ago, and I was pretty upset, but this is the first time I have really missed it up there in a long time. Have fun, and feel free to pm me if you want more details.