Here’s some more fishy advice.
I spent a lot of years as a mate, fishing, or running head boats; the first thing we would do is as soon as the anchor is set head up to the forward beam of the boat. If it’s not packed, there should be plenty of room to cast your spinner out as far as you can.
Instead of using a small piece of squid, use a whole piece without the head and tentacles. Hook the tail end of the squid and place a stinger hook toward the fat part.
Depending upon the current; use a one or two ounce weight, above the swivel in a slip style fashion. Cast this out as far as you can off the side of the boat and let it sink close to the bottom, then reel it in slowly like a swimming lure, keeping it off the bottom to avoid a rock up.
Remember where there are grunts there are predators, amber jack, and snapper; most predators move away from the boat as it maneuvers to anchor, and your best bet is to get the bait away from the boat's prop wash.
I’ve found that this works more that not; after you’ve run your bait a few time, hit the bottom with the rest of the guys, unless you like free lining off the stern where you have the same opportunities for top and mid depth fish.
This works especially good in the keys where the ½ day boats fish the patch reefs, same theory.
Good luck, wish I was going with you!