Steering Twin-Engine Boats: Mastering The Art Of Control

Steering a boat with twin engines can be intimidating, especially when docking in crowded marinas. However, twin-engine boats offer more manoeuvrability and control than single-engine boats, especially at low speeds. The key to successfully steering a twin-engine boat is to understand the dynamics of the propulsion system and practice handling the boat in calm conditions.

When docking a twin-engine boat, it is important to prepare by deploying fenders and lines, and being aware of wind and current conditions. One effective technique is to use only the shifters and throttles to control the boat, as the rudders are generally ineffective at slow speeds. By manipulating the throttles and shifters, the boat can be pivoted and steered in the desired direction.

Practising these techniques in a controlled environment will help boat owners gain confidence and familiarity with the unique handling characteristics of their twin-engine boat.

Manoeuvring with twin stern drives

Manoeuvring a boat with twin stern drives can be more challenging than expected, especially the first time. Twin engine boats provide more manoeuvring control than a single engine boat, as they can push or pull from both corners at the stern, allowing for more directional changes without the wheel.

Stern drives are an articulating steering system, which means the wheel turns the twin drives, redirecting thrust. However, unlike an outboard, you can't see them from the helm, so it's important to pay attention to the steering wheel when docking and for close-quarters manoeuvring.

Manoeuvring techniques

There are a few different techniques for manoeuvring a twin stern drive boat. One method is to use only the shifters to steer and keep your hands off the wheel. This can be tricky, as even a small turn of the wheel can change the drive's angle of thrust.

Another method is to use the wheel and one or both drives. This makes things happen more quickly, which can be necessary when there is wind or current. In calm conditions, you can use the shifters alone with a centred wheel. Use short shifts and a certain amount of drifting in neutral to control momentum.

Docking

When docking a twin stern drive boat, it's important to know your boat's handling characteristics and which technique works best for you. In general, when docking, it's recommended to use the wheel to make things happen more quickly.

The ARC method

One specific method for docking a twin sterndrive boat is the "ARC method". This method is said to be superior when it comes to manoeuvring in tight quarters in a marina and when docking in a slip or parallel at a dock. It involves using the wheel to dock, and it has been proven to be effective in all types of wind conditions.

Docking a twin-engine boat

Prepare for Docking

Before you begin the docking process, it is crucial to prepare your boat and yourself. Ensure you are familiar with your boat's handling characteristics and have a clear understanding of the wind and current conditions. Deploy fenders and lines as necessary, and check that the wheel is centred.

Trim Your Engines

Use the tilt-trim switch at the throttle to trim your engines slightly upwards. This ensures that the propwash goes under the boat, maximising its manoeuvrability.

Approach the Dock

As you approach the dock, maintain a 90-degree angle. When the middle of your boat is aligned with the middle of the slip, stop and centre your steering wheel.

Spin the Boat

Now, it's time to spin the boat by opposing the engines. Shift one engine into forward and the other into reverse. Remember, do not touch the steering wheel during this step, rely solely on the engines for manoeuvring. The bow will move in the direction of the throttle shifted into reverse. For example, shifting the starboard throttle into forward and the port throttle into reverse will spin the bow to port.

Adjust and Correct

In ideal conditions, with no wind or current and ample space, you can spin the boat until it is parallel with the finger pier. Then, simply shift both engines into reverse idle and back into the slip. However, you may encounter space constraints or unexpected gusts of wind that require corrective manoeuvres. If you can't spin the boat completely, remove the forward throttle from the gear to stop the forward thrust. This will allow the boat to continue spinning while backing up, getting it closer to the slip. Adjust the throttles to find the right balance between spinning and backing up.

Final Adjustments

As the boat moves into the slip, you may need to make final adjustments. Reverse both throttles briefly to stop any spinning motion, then back slowly into the slip. If the bow is not aligned correctly, make light adjustments by shifting starboard reverse or port forward to bring the boat alongside the dock.

Know Your Boat Type

The procedure for docking a twin-engine boat varies depending on whether you have twin inboards, twin sterndrives, or twin outboards. Twin inboards have propellers and rudders under the boat, while twin sterndrives and outboards have propellers and outdrives behind the boat. The handling characteristics and thrust dynamics differ significantly between these types, so be sure to familiarise yourself with your specific boat type.

Practice Makes Perfect

Using the steering wheel

When docking a twin inboard, it is generally recommended not to use the wheel. The reason is that adding the wheel to the shifts and throttles can overload the captain's brain, leading to confusion and mistakes. By not using the wheel, you have more control and can manoeuvre the boat effectively without overcomplicating things. However, some advanced manoeuvres may require the use of the wheel after gaining several seasons of experience.

On the other hand, when docking a twin sterndrive or outboard, the recommendation is to use the wheel. These boats have propellers and outdrives that turn for steering, similar to an outboard motor. By using the wheel, you can direct the thrust and make controlled turns. However, it is crucial to return the wheel to the top dead centre (straight ahead) after each turn, or the boat won't go straight or pivot as intended.

The type of docking manoeuvre also plays a role in whether to use the wheel. For example, when backing into a slip, it is generally recommended to oppose the engines (one in forward, the other in reverse) without touching the steering wheel. This allows for a quick spin, and the boat can be manoeuvred into the slip by adjusting the throttles.

In summary, while the steering wheel is an essential component of boat steering, the decision to use it or not depends on the type of twin-engine boat and the specific manoeuvre being performed. Practising boat handling in calm conditions and understanding the boat's response to controls are key to becoming a skilled captain.

Turning on one engine

If one of your two engines breaks, berthing becomes more challenging, but you can still get home. It is worth practising this in advance, preferably on a calm day with plenty of space.

Twin-engined boats have offset engines and two smaller rudders, so if one engine fails, it is easier to turn in one direction than the other. If you have enough space to turn around using just the working engine, turn in the direction the boat wants to go, with the engine on the outside.

If you have a shaft-drive boat with limited room to manoeuvre, it is easier to steer the boat against the working engine. This is because there are three factors that affect the steering of a twin-shaft boat: prop offset, prop walk, and the rudders. Prop offset refers to the distance of the propeller from the centreline, which affects the steering. Prop walk is the sideways travel all propellers produce, especially in reverse. The rudders are more effective when moving forward than in reverse due to increased water flow from the propeller thrust. Knowing these dynamics will help you use them to best effect.

If your port engine is dead and your starboard one is working, and you turn the boat to port (the way it wants to), you will have all three factors working for you. But the moment you go in reverse, they will all work against you. The better option is to turn to starboard, against the working engine, and use the rudder to overwhelm the other two factors. Going forward, the offset and prop walk will be against you, but you can overcome them with extra revolutions to increase water flow over the rudders.

Once you have turned through the first 50° or 60°, take the boat out of gear. Now there is no offset or prop walk to fight against, but the flow of water over the rudders will keep the boat turning. When you engage reverse, the prop offset and prop walk will be working for you. You won't even need to adjust the rudders as you won't be going astern quickly enough for them to have an impact. These two factors alone will drag the stern through the remainder of the turn, completing the 180° spin in a controlled manner.

Docking a Twin-Engine Boat

Preparation is key. Observe wind direction, current or tidal run, other vessels in the area, and pedestrians on the dock. Make sure everyone on board who is not involved in the docking procedure is seated or out of the way.

Commence your approach from an appropriate distance, depending on how much room is available. Start your approach from about 30m away, coming in at a shallow angle to the dock, around 30°. Identify the cleat on the dock that you will aim to tie up to.

At slow speed, there is not enough water travelling past the rudder, so it becomes ineffective. Using the engine controls, turn the boat by placing one of the engines in neutral. For example, placing the port engine in neutral and leaving the starboard engine engaged will cause the boat to turn to port.

Coming in to tie up on the starboard side, place the port engine in neutral about half a boat length away from the dock. With the starboard engine still engaged, the boat will swing in a gentle arc to port. As the boat continues to swing to port, place the starboard engine in neutral. With both engines now disengaged, the boat will continue its forward momentum. Wait for the rear cleat on your boat to align with the cleat on the dock.

Once you are close to the dock, you can make some gentle corrections. For example, if it looks like you will go past the cleat, you can engage the port engine in reverse. Or, if you lose forward momentum before the cleats are aligned, you can engage the starboard engine forward.

Once the vessel is positioned and stationary, move to the stern. Take your pre-prepared line attached to the stern cleat, cast it over the cleat on the dock, and fasten it back to the boat. The boat is now secured to the dock. Engage the starboard engine, which will cause the boat to spring off the stern line and move towards the dock. Leave the starboard engine engaged and step off the boat to secure the rest of the lines.

Docking in crowded marinas

Docking a twin-engine boat in a crowded marina can be a nerve-wracking experience, but with practice, it will become second nature. Here are some detailed instructions to help you master the art of docking in crowded marinas:

Stay Calm and Avoid Hasty Control Actions:

It's natural to feel pressured when docking in a crowded marina, but it's crucial to stay calm. Many boaters panic and make abrupt control adjustments, leading to loss of control. Take your time, and remember that you can always restart if needed—there's no shame in that.

Practice Makes Perfect:

Expert boat handling requires both knowledge and practice. Dedicate a day for a practice session in a calm area with plenty of space. Practice basic manoeuvres, such as turning the boat, stopping, and holding it steady. Familiarise yourself with various control combinations to avoid confusion during docking.

Understand Basic Principles of Twin-Engine Control:

Twin-engine boats offer precise control. At idle speeds, control the boat using only the throttles and shifters, not the steering wheel. The rudders are ineffective at slow speeds, so rely on engine power to pivot and turn. Practice using different throttle and shifter combinations to understand how your boat responds.

Approach the Dock:

When approaching a T-dock, ease the bow of your boat within 10 feet of the dock, perpendicular to it. If you have a bow pulpit, position it to the right of a piling to avoid damage. Use the pivoting technique by putting one engine forward and the other in reverse to rotate the boat into the dock.

Use Wind and Tide to Your Advantage:

Always be mindful of wind and tide conditions. Dock into the wind or tide if possible. If there is a strong current, practice holding your boat in one spot against it. Learn to judge wind direction and current speeds to make them work for you during docking.

Backing into a Slip:

Backing into a slip is challenging, especially in crowded marinas. Use pivoting techniques by finding a piling to steady your boat against. Keep one engine in forward and the other in reverse to pivot smoothly without losing control. Be alert to wind and current conditions and adjust as needed.

Remember, practice is key to mastering docking with twin engines. Take the time to understand your boat's handling characteristics and how it responds to different control inputs. With patience and persistence, you'll soon be docking with confidence, even in the busiest of marinas.

Frequently asked questions