The problem here seems to me to be that water
toys are not competent dinghies, which can actually be pretty good boats. Your Coleman one has a flat bottom, and will be very difficult to steer straight and row upwind. Try to think about and imagine why inflatable dinghies have bows designed differently from your raft. Some inflatable dinghies also have flat bottoms, skitter sideways a lot, and as a result, outboard
motors for them are popular. Early efforts at mounting o/bs on round transom dinghies showed that strong transoms are needed to allow the transfer of power to propel the boat.
Maybe you could talk someone with a proper rowing dinghy to let you try rowing it, especially upwind in a breeze, it to experience the differences for yourself. But for the purpose of setting out a second anchor
in a blow, you'll really need a good "pulling boat" or a good engine
, or you'll try to figure out another way to do it.
If you're happy to try to use your Coleman for a while and let it prove to you its incompetence as a boat [even though you enjoyed it as a river raft], as long as you're careful, you should learn from the experience. Do not expect it to be as stable as a dinghy that is designed as such.
When you get around to choosing a dinghy for your "big boat", here's something to consider: will it still float if one chamber empties? If you have only one fill/empty valve, all the air can go away from valve failure (not uncommon), and of course, puncture can be a problem, too--mind those oyster
shells, they cut up pvc, and even hypalon. Another thing to consider is whether the freeboard will be adequate for two people at the same time. Dinghies carry people and goods to and from their "big boats", and reserve buoyancy is important.
Some people prefer large, competent dinghies so they can leave the big boat safely anchored and explore by dinghy.
Just a little food