Stopping the boat on command: hold water, blades down, stop or stop one side only. The sequence from DRV rowing commands, the pressure limit and safety rules.
The honest answer up front: you stop a rowing boat on command in two steps: first "hold water", then "stop": the blades are pressed into the water and, as far as the pressure allows, carefully turned. That is how the excerpt "Rowing commands" from the German Rowing Federation (DRV), after "Bootsobleute und Steuerleute", describes it [1]. The command is safety knowledge, because a rowing boat has no brake and no reverse button.
What is the danger when stopping? The DRV states it clearly: too much pressure is either not tolerated by the oarlocks, which are not built for pressure in this direction, or the blades break off, or the handle pushes the rower out of the boat [1]. In plain words: stopping is braking with feel, not ramming in.
When do you need it? For example for an obstacle ahead. In an exam question of the DRV coxswain and bow-person test, the correct answer for a suddenly appearing groyne is "Hold water! Stop port" or "Hold water! Stop!" [2]. And: according to British Rowing, collisions are a frequent cause of capsizes [3].
How hard is it? You learn the commands in one session. Executing them correctly under stress takes several training sessions, in experience terms. This guide does not replace instruction in the boat.
Rowing commands consist of a preparatory and an executive part. After the preparatory part there should be enough pause for the crew to concentrate [1]. Milestone: you can recite the order "Hold water, Stop, stop".
At "Hold water!" the preparatory part comes at blade entry, the executive command at the end of the drive. After the stroke, the feathered blades are carried above water toward the bow until the oars stand perpendicular to the boat [1]. The boat runs out.
With "Blades down!" the blades are laid flat on the water [1]. That stabilizes the boat. Milestone: the boat sits calmly, without jolts.
At "Stop – stop!" the blades are pressed into the water and, as far as the pressure allows, carefully turned [1]. So press only as hard as boat and equipment can take. Anchor: you brake like a hand lever on a bike, not like an emergency brake.
With "Port (starboard) stop – stop!" you stop one side only. All stopping has the largest effect in bringing the boat to a standstill and moving the bow aside when an obstacle appears exactly in the direction of travel [1]. Milestone: in training with a coach you hit the sequence three times without a mistake.
Practice stopping in three steps: first "Hold water" and watch how far the boat runs out, then "Stop" at low speed, then one side. Note in boat lengths how far your boat ran out. You will need that number in an emergency. Measuring beats guessing.
The command to stop after the stroke with feathered blades. The oars are carried perpendicular to the boat and the boat runs out [1].
With "Hold water" and then "Stop – stop": the blades are pressed into the water and, as far as the pressure allows, carefully turned [1].
Oarlocks are not built for pressure in this direction, blades can break, and the handle can push the rower out of the boat [1].
Only port or starboard stops. It turns the bow sideways, for example to avoid an obstacle or to prepare a turn [1].
Backing Down: Rowing Backward With Reversed Blade Position