I grew up over there and used to mooch live herring this time of year. There are many different places to go such as the Bargain Harbour area, Sargents Bay, bottom end of Thormanby Isl. My advice would be to go just outside the mouth to the Secret Cove. Anchor in about 150-200 ft of water, put the herring down to bottom and reel up 20 times. That is just a basic description of what we did, you can obviously play with different depths, both anchoring and your bait. Hopefully you'll see another boat out doing the same thing, but I wouldn't count on it. We didn't have a live-well, so in our case we needed to bring two buckets to constantly keep the herring happy by recycling the water every once in a while.
You can prawn right close to where you mooch but in 300ft give or take a bit, you should see other floats (make sure it is open, I haven't been there in a while) and crabbing is good over in Buccaneer bay likely.
PM me for any other info. Mooching live herring is really fun!! I hope you get a chance to go try it out. Don't bother trolling without riggers this time of year IMHO.