Hi,
EDIT: Never mind, I figured it out. The straight waterway sections do not show the signal placement markers like straight rails do, instead you see the train/wagon position markers. But you can place the buoys at any position if you try at the right distance from the waterway. My apologies for any confusion I may have caused...
First of all: I really love your mod, it is so cool to use and watch the ships.
However, I am struggling with the placement of signals/buoys: with rails and rail signals there are many places where these can be placed (everywhere at straight stretches and at limited places in bends), but with waterways it seems I can only see the placement markers in bends, and only a few actually allow me to place a buoy. At long straight stretches I see no placement markers at all. This means that only a single ship can occupy that entire stretch, making hard to create long shipping lanes that are used by multiple ships. The only way I found to do that is to zig-zag now and then so that the curves will allow buoy placement.
It also makes connecting these routes to ports/docks difficult because it is hard to place signal buoys to manage all the crossing waterways.
Is this a known problem, or am I doing something wrong? I am running Factorio 0.17.45, but the problem has been there since I added Cargo Ships around 0.17.43 or so. I disabled all other mods, but the problem persists.