SVOP Boat Handling 2 — Questions and Answers

Question 1: When manoeuvring a small vessel in reverse, which side does a single right-hand propeller typically cause the stern to walk toward?

Port (left) (Correct answer)
Starboard (right)
Straight astern
It depends on vessel speed

Correct answer: Port (left)

A right-hand (clockwise) propeller in reverse causes the stern to walk to port due to propeller torque and the paddle-wheel effect acting on the lower blade, which has greater bite.

In a single-screw vessel with a right-hand propeller, engaging reverse causes the stern to swing to port. This is the 'paddle-wheel effect': in reverse, the lower blade of the propeller (which moves through denser water) exerts more lateral force than the upper blade. For a right-hand prop, this pushes the stern to port. Skilled mariners use this tendency — for example, backing into a port-side berth — by letting prop walk assist the manoeuvre rather than fighting it.

Question 2: What is the safest approach angle when coming alongside a dock in calm conditions?

30 degrees, reducing to near-parallel (Correct answer)
90 degrees directly broadside
45 degrees maintained throughout
10 degrees at high speed

Correct answer: 30 degrees, reducing to near-parallel

A 30-degree approach lets you control speed and pivot the stern in at the last moment with a burst of reverse or a spring line. Steeper angles risk a broadside collision; too shallow reduces control.

The standard alongside approach in calm water uses roughly 30 degrees to the dock. This angle gives good visibility, allows speed to be kept low, and permits the operator to pivot the bow away or kick the stern in with a short burst of reverse. As the bow nears the dock, crew secure a bow spring line. The helm is then turned toward the dock and a brief forward thrust pivots the stern alongside. In stronger winds or current the angle is adjusted — typically steeper when heading into wind/current to maintain control.

Question 3: When must an operator use a kill switch (engine cut-off) lanyard?

Whenever the operator is the only person aboard or when required by the vessel's design (Correct answer)
Only in waters with a posted speed limit
Only when children are aboard
Only in rough weather above 2 m waves

Correct answer: Whenever the operator is the only person aboard or when required by the vessel's design

Transport Canada requires operators to use a kill switch lanyard whenever it is provided and when they could be thrown from the helm, preventing a runaway vessel after a fall overboard.

Under Canada's Small Vessel Regulations, a kill switch lanyard (engine cut-off device) must be worn by the operator when the vessel is equipped with one and the operator is in a position to be thrown from the helm. This is especially critical on open powerboats where the sole operator could fall overboard. If the operator falls, the lanyard disconnects the switch and kills the engine, preventing the vessel from continuing on without control — which could run over the person in the water or collide with another object. This is a fundamental safety requirement on the SVOP exam.

Question 4: What effect does shallow water have on a vessel's handling?

Squat increases, stern sinks, steering becomes sluggish (Correct answer)
The vessel rises and becomes more responsive
Speed automatically increases due to the venturi effect
Trim improves as pressure builds under the hull

Correct answer: Squat increases, stern sinks, steering becomes sluggish

In shallow water, flow is restricted under the hull, causing the bow to rise slightly and the stern to squat. Steering response deteriorates and the vessel may be drawn toward the bank (bank effect).

The shallow water effect (also called squat) occurs when a vessel travels through water where the depth is less than about 1.5 to 3 times the vessel's draft. The high-speed water flowing under the hull cannot replenish quickly enough, causing a pressure drop that sucks the vessel down — especially at the stern. The result is increased draft, reduced helm response, and the risk of grounding. Operators should slow down significantly in shallow water. Additionally, bank suction can draw the bow toward a nearby bank while the stern swings away from it.

Question 5: What is the purpose of a spring line when berthing?

To prevent the vessel from moving forward or backward along the dock (Correct answer)
To hold the bow tightly against the dock
To keep the stern away from the dock during high tide
To act as a tow line if the engine fails

Correct answer: To prevent the vessel from moving forward or backward along the dock

A spring line runs at an angle forward or aft along the dock and prevents the vessel from surging ahead or dropping astern while alongside, complementing breast lines that hold it laterally.

Spring lines are mooring lines that run at an acute angle to the dock — a forward spring runs aft from the bow toward the dock, and an after spring runs forward from the stern. By tensioning a spring and applying a gentle engine thrust against it, a skilled operator can also pivot the vessel's bow or stern away from the dock when departing. In tidal ports, springs allow the vessel to rise and fall with the tide while staying positioned against the dock. They work together with bow, stern, and breast lines to fully secure a vessel.

Question 6: What is 'leeway' in vessel operation?

The sideways drift of a vessel caused by wind or current acting on the hull (Correct answer)
Extra clearance kept between vessels at anchor
The distance a vessel overshoots when stopping
The angle of heel when turning at speed

Correct answer: The sideways drift of a vessel caused by wind or current acting on the hull

Leeway is the lateral displacement of a vessel from its intended track, caused by wind pressing on the topsides and current pushing the hull sideways. Operators must correct for it by adjusting course.

Leeway is the angular difference between the course steered and the course actually made good over the water or ground. When wind blows on the beam (side) of a vessel, it pushes the hull and superstructure downwind. Similarly, a beam current sets the vessel sideways. To compensate, the helmsman steers a few degrees into the wind or current so the vessel tracks along the intended course. Leeway is most significant on vessels with high freeboard (large above-water profile) and must be accounted for when planning passages and approaching hazards.

SVOP Boat Handling 2

When manoeuvring a small vessel in reverse, which side does a single right-hand propeller typically cause the stern to walk toward?