Harbor maneuvers
They are not learned from books?
Our sailing training course
Boating, harbor maneuvers
The Mediterranean case: stern-to mooring with lazy line
The majority of collisions between pleasure boats occur during harbor maneuvers.
Dear fellow boaters, here is a recap of the basics of maneuvering under power... To be repeated until perfectly mastered!
Propeller walk, friend or enemy?
A basic element of maneuvering under power, propeller walk is the lateral influence of the rotation
of the propeller on the boat’s movement. It is always stronger in reverse gear and must therefore be taken into account during maneuvers.
The principle
A propeller works thanks to the pitch of its blades. This pitch means that any propeller pushes water at an angle.
When moving forward, the propeller pushes water onto the rudder, which through its orientation compensates for the lateral effect of the propeller.
In reverse gear, the propeller pushes water forward, and there is no rudder to reduce this lateral effect: the boat moves diagonally until speed is sufficient for the rudder and keel (or centerboard) to bite into the water flow and allow steering.
It is therefore in reverse gear that propeller walk is strongest. You must therefore always take it into account during engine maneuvers.
Determining the direction of propeller walk
By convention, the direction of propeller walk is defined with respect to forward gear. For example, a so-called “left-handed” propeller will have an effect to the right in reverse, and vice versa.
1-stop the boat head to wind or downwind
2-engage the throttle with a “burst”* in reverse gear
3-observe the direction in which the boat turns: if the stern moves to the left, the propeller walk is to the left in reverse, and vice versa.
*the “burst” consists of giving a strong throttle input in reverse or forward (up to about 1800–2000 rpm) and then returning to neutral. It allows maneuvering using propeller walk without building up speed.
Turning on the spot
Most of the time, there is not enough space in harbors to turn using forward or reverse gear alone. You must therefore proceed in stages: the available space ahead of and astern of the boat will determine the number of forward and reverse movements required to complete the turn.
For a left-handed propeller in reverse:
-turn the helm toward the side you wish to turn when moving forward
-give a throttle burst in forward gear
-return to neutral before the boat builds up speed*
-give a burst in reverse gear: the boat turns to the left in reverse thanks to propeller walk (no need to use the helm since the boat does not have enough speed for the rudder and keel to bite into the water)
-continue alternating forward and reverse until the turn is completed
*speed is always dangerous in a harbor as it prevents you from stopping your boat quickly if needed
Nota bene: always favor a turn with the reverse propeller walk on the windward side of the boat.
For example, if your propeller walk is to the left in reverse, the boat will turn much better with the wind coming from port (port tack)
Five steps to properly prepare a maneuver
1-The skipper must take the time to analyze the situation by observing the water area: Where must my sailboat or motorboat be positioned? What are the wind and current like? What constraints will I have to deal with, etc.
2-choose a strategy
3-Explain the maneuver to the crew
4-Prepare the boat (lines, fenders) and position the crew
5-Action!
Approaching a pontoon under power
-place fenders along the entire length of the hull at pontoon height
-move the boat four to five boat lengths away from the pontoon
-set a trajectory at about 30° to the pontoon
-aim for the part of the pontoon where the stern will be positioned once stopped
-regulate speed so as not to exceed 1.5 knots, otherwise you may not be able to stop the boat easily
-place someone in the shrouds to help the helmsman judge distances on arrival
-in the final meters, gradually bring the side of the boat closer by alternating helm left and right (an “S” trajectory)
-stop the boat parallel to the pontoon with a reverse gear
-disembark the crew at the shrouds
-moor the boat
Nota bene: never persist with a poorly started maneuver. It is better to abort and start again on a sound basis!
Mooring lines
There are two main types of mooring lines:
Bow and stern lines are short lines at the front and rear of the boat. They keep the boat parallel to the pontoon. Since the hull is rounded, the middle of the boat presses against the pontoon. This is therefore where the most fenders are placed. Bow and stern lines should be slightly slack to avoid crushing the fenders against the pontoon.
Springs are longer lines that run from the bow and stern of the boat to the middle of the pontoon. They prevent the boat from moving forward and backward. The spring attached at the bow is called a forward spring, and the one attached at the stern is called an aft spring.
Nota bene: it is said that you first cast off the slackest lines (those that serve no purpose).
Three main scenarios for arriving at or leaving a pontoon
Case No. 1: The wind presses the boat against the pontoon
Arrival
Even if you stop your boat far from the pontoon, the wind pushes you onto it. This is the easiest case for an arrival.
Departure
To depart, you will need to move the boat away from the pontoon or you risk scraping the hull against it.
In this case, a forward or aft spring is used to pivot the boat on the rounded hull. You then have the choice between a departure on the forward spring or the aft spring. If the wind comes more from ahead, it is better to depart on the aft spring. If the wind comes more from astern, depart on the forward spring.
Departure on forward spring
-place fenders from the middle of the boat to the bow. If possible, place a crew member at the bow with a fender held by hand (a “flying” fender) to properly protect the bow
-run the forward spring around a pontoon cleat and lead it back to the bow so it can be released from the boat
-remove the other lines
-engage forward gear gently, helm straight until the forward spring is taut
-turn the helm to make the boat pivot toward the pontoon. The boat rests on the fenders closest to the bow and the stern moves away from the pontoon.
In strong winds, increase forward throttle to help push the stern away from the pontoon.
-when the boat is oriented at 45° to the pontoon while resting on the bow, shift to neutral then engage light reverse gear
-recover the spring on board
-make sure the boat is far enough from the pontoon to move ahead
-engage forward gear and proceed
Departure on aft spring
The maneuver to depart on an aft spring is the same in reverse, with the engine engaged astern until the stern of the boat is positioned at 45° to the pontoon, resting on the fenders placed closest to the transom.
Case No. 2: The wind pushes the boat away from the pontoon
Arrival
As soon as your boat is stopped, the wind will push it away from the pontoon. You will therefore need to:
-stop your boat close enough to the pontoon so the crew can step ashore
-ask the crew to be ready to disembark to moor the boat
Departure
This time it is easier because the wind helps you! Simply cast off springs and bow/stern lines and let the wind push the boat away from the pontoon.
Our advice: cast off the bow and stern lines from the boat.
Case No. 3: The wind blows along the axis of the pontoon
In this case, it is always better to arrive head to wind (or head to current if it is stronger) in order to slow the boat effectively.
If the wind is moderate, start by securing the bow and stern lines, then the springs.
With a strong headwind or current, you can start by mooring the boat with an aft spring and a bow line, then the other lines.
With a strong following wind or current, you can start by mooring the boat with a forward spring and a stern line, then the other lines.
Key points to remember
- in harbors, speed is a risk factor
- wind pushing the boat onto the pontoon: easy arrival, departure on forward or aft spring
- wind pushing the boat away from the pontoon: delicate arrival, easy departure
- it is always better to arrive head to wind (or head to current if it is stronger) to stop the boat easily