Why not only beginners should paddle flatwater

In canoeing it's an often mentioned topic "I already know how to paddle, I don't need flatwater anymore". This is often said by people who consider themselves as more or less advanced paddlers, having stepped out of the pond.

For beginners people think it's logic to start on flatwater. After all, if we drop a beginner in a canoe en into an easy class II river, we'll probably end up fishing out paddler, gear and boat. No, when we're learning to paddle, we want to minimize the environment factors as much as possible so that we can focus on learning how to get a hold on that canoe and paddle thing. But once we know how to paddle a straight line, we want to move out to the river, and never come back to flatwater, or at least not frequent (exceptions are there, I'm aware of that).

Canoeing Versus Tennis

Personally this approach is a bit weird for me, canoeing seems to be one of those sports where you're supposed to learn everything during the competition. I'll make the comparison with another  sport, say tennis (which I don't play btw).

The evolution of a tennis player

When people start to play tennis, they first learn to hold their racket, hit a ball with that racket and try to keep the ball between the lines. It's isolated: explain the grip, explain the forehand move, the timing, ... . People of the same level can have with this very basic level, tons of fun! They can even challenge each other for a little competition in a match.
But soon one discovers that a backhand is a nice move to have in the repertoire, and maybe an overhand service looks cooler and is more efficient. Our two beginners work it out together, or with an instructor, and progress into new moves. After a couple of matches against each other, they even might  participate in the club-championship. There they discover the club champion has some exotic moves like slices, drops, ... . More things to work on, but not during the game. When you try out that new stroke during the game, that's the perfect move to loose that match.

Having more strokes also means you have to develop in insight in when to use which move. But still, plenty of new moves, good insight does not add up to compete against the club champion. He makes up the difference by just a little more subtle racket positioning, a little finer stroke, a little better strategy, ... . And there our two beginners - being quite advanced tennis players by now, go back to their trainingsessions to get a feel for this finesse and finetuning. With enough training and finetuning and talent, they might even win bigger competitions and tournaments.

The evolution of a canoe paddler

Now how does learning to play tennis corresponds to  learning how to paddle? The start is the same, we get into our canoe and learn how to work the canoe and the paddle. This on itself can already be lots of fun. The competition can become our first river trip. We have an external challenge, not an adversary like in a tennis match, but the river. Here we have to learn how to use the force of the river and not fight it. There comes a point where we have a reasonable feeling for the river and how our canoe behaves on moving water. But many paddlers also notice some shortcomings when paddling moving water. There are some strokes missing in their repertoire. Or maybe not the strokes, but at least some moves just don't work. This is the point where the tennis players realize they need a backhand and an overhand service. But instead of stepping back to flatwater, paddlers tend to try it during the game, on the river. At this phase it takes a couple beatings, and plenty of swims to get a rough new technique, learned on the river.

By paddling harder water, we discover you even need more moves, more advanced strokes, which are very often only practiced on the river. And if we're lucky, we might realize that we have quite some finetuning to do on our repertoire. But finetuning on the river might get hard for some strokes, since we don't have an isolated environment.

So why not step back to flatwater for new moves, for finetuning, ... ? Almost any other sport steps back to some level of isolation to learn or optimize new moves. If you need a backferry for example, then the first requirement is that you have good backwards paddling canoe control on flatwater. After all, if  you can't paddle backwards on the river, how would you be able to do that on a river with extra influences? This principle goes for a lot of strokes and moves in the sport of canoeing: if you can't do it on flatwater, you certainly can't do it on the river (again, some moves you can only practice on rivers, and always exceptions are there).

I'm not pleading that people should have a perfect boat control on flatwater before they hit the river. Of course you can challenge a better tennis player, but you don't want to challenge a WTA ranked player if you only just have learned an overhand service and a sloppy backhand. And even WTA ranked players train in isolation on their service, backhand and so on.

Conclusion

Flatwater is for canoe paddlers a great way to add new strokes to their repertoire or to improve their existing repertoire. It all depends on your ambitions. If your ambition is to become a WTA ranked tennis player, there is no way around working hours on those basic drills. If you're happy with a club championship once in a while, it might be ok to work on a good basis. For paddling it's the same, the further you want to go, the more you need to step back to flatwater and work on the basics, like in any other sport.