Bill, My jack and lug wrench from my Tacoma are a good match. I’m wondering if I should bolt the spares to the trailer? Maine has a great reputation for honest folk so I wouldn’t worry about theft at boat ramps, just curios if this is a common practice. I have never owned a boat trailer.
Bolting spares to the trailer, in a perfect world, is definitely the most convenient. The spare tires are never left behind, and the tow vehicle does not need to be unloaded to get to the spare.
Locking devices for mounting spares are available that deter the less aggressive, but in a world of battery powered angle grinders, nothing locked down is safe today.
I personally carry my spare within my tow vehicle, but that is primarily because all of my trailers live outdoors, and none of the boat covers would also protect a spare mounted to the trailer, and I'm not running the sort of rigs that would feel right with a separate cover on the spare. UV exposure in Louisiana prematurely damaged a couple of my spares, decades ago, so I haven't mounted the spare to any of my trailers because of simply keeping them out of the sun, but that should not be an issue for you, because of your ability to store indoors.
If you do buy a mount to attach your spare, or spares, make sure that the lug nuts for that spare tire mount, are the same size as those on the trailer hubs.
And if I were to buy a device to mount a spare to the trailer, I would upgrade to the style that allows not only the spare, but also provides for the mounting of a spare hub along with the spare tire.
The combination of having a spare hub, with it's bearings, grease and seals, along with a spare tire, will get you home most of the time.
I think there are equally as many trailer hub bearing/grease issues disabling boat trailers as flat tires. Hot hubs hitting cold water when launching repeatedly between maintenance intervals, requires more routine maintenance than most realize. I don't hook up to a trailer without having topped off hub grease, and checking for any play between hub bearings and axle, as well as confirming proper tire pressure. I also pull the hubs annually, inspect bearings and seals, and change either the hub oil and/or grease.
I may be preaching to the choir, just now remembering that you have probably a zillion miles pulling really loaded trailers. But also not sure how many times you backed those trailers into cold water with warm hubs. Disregard if needed.
Bill