Radio doesn't care how fit your crew is — bodies, bridges, and the bend of a river all block signal. Repeaters fix the physics.
The physics
Athlete bodies block radio.
Radio fades fast behind people, bridges, buildings, and other boats — eight rowers between an RPX and the launch soak up signal. A repeater sits above the problem: give it clear line of sight and your data travels around whatever's in the way.
Placement
Put it where it can see.
Repeaters live on boats. On the coach launch, mount it on the side of the boat or at a high point — antenna vertical, clear line of sight to the athletes. Spread-out crews? Put one on an athlete boat instead: the stern of the lead boat, facing back toward the coach, keeps it in range of both the crew and the launch as the pack moves.
Lead boat
Stern, facing back
One or more
Repeaters self-organise into a mesh.
No pairing, no setup — turn one on and every RPX in range joins automatically. Add more repeaters and the mesh hops between them for up to several kilometres of coverage, as long as each repeater stays within roughly 300 m of the next.