Sailfish, don't you have 12vt power on the boat? Car charger plugged into a power port or HotWired should keep you topped off on the water, but I would recommend a back up like solar. Big batteries are great, but without recharge capability, it will not even pound tent stakes well.
The only real difference between a good tracker and a bad tracker is observation. All the same data is present for both. The rest is understanding what you are seeing.