“Good morning Captain. Your mission should you choose to accept it, is to dock your twin engine boat with one motor shutdown.
As always, should you or any member of your crew be………. This tape will self destruct in five seconds.”
Is this another “Mission Impossible”? For details of your mission........
You know the main advantages to buying a boat with twins:
- Better maneuverability
- Better performance for a larger boat
- Assurance you still have power if one engine quits
BUT, what if one quits? Whether Twin Outboard, Twin Sterndrive or Twin Inboard?
Do you know how to handle and dock your twin with just one live motor? It’s totally different than docking with both motors running, and it is quite different than docking a single engine boat. How so?
On a single engine boat, the motor is on the centerline of the transom and the thrust is therefore balanced; whereas, on a twin, the motors are off center.
Therefore, when operating a twin with only one motor, the thrust is off center and unbalanced, creating differences from handling a single as well as several challenges to be prepared for.
The major difference is that your turning radius will be greater or much, much greater, depending on which direction you are turning and which engine is dead. Look below in “Lessons Out on the Lake” to find out which is which and how to outsmart them.
When the motor with the power steering pump dies, you will quickly discover how much work your power steering pump actually does for you. It will be like trying to push a shopping cart with one back wheel seized. It doesn’t steer or maneuver easily at all.
If you believe in Murphy’s law, it is will be the motor with the power steering pump on it that quits. So, turning the wheel will be difficult, which changes from you palming the wheel around, to having to use two hands to pull it around. Knowing this, you want to make each turn count to the maximum to reduce the number of times you have to turn the wheel from hard over to hard over.
On that weekend when there is nowhere to go and nothing pressing to do, I recommend you spend half an hour with only one engine running—leave the other off. Practice handling and docking your boat. Then repeat with only the other engine. This practice will prepare you, if you are ever caught with one engine that just won’t co-operate.
Lessons for Out on the Lake
Start in open water. Your first exercise is to execute a hard-over turn with your running motor on the outside of the turn. Let’s assume it’s your starboard engine that’s running and your port engine is dead and; therefore, you are turning to port. The bow will come around to port in a gradual curve. To tighten this curve, give a short shot of throttle, slow it, then pull into neutral. Watch it turn tighter as the whole boat tends to rotate or fish tail, as well as continue on the turn to port.
You would expect that to tighten this rotation to port even more, you would pull the running (starboard) motor into reverse.
- On a Twin Sterndrive or a Twin Outboard, turning the wheel hard over the other way, then reverse will help.
- On a Twin Inboard, when you pull your starboard (outside engine) into reverse, the back end stops swinging and actually reverses against the swing—back on the track just travelled. So, no reverse or very short reverse.
The second exercise is to turn against your running motor. Using the same motor as in the previous exercise, our starboard engine is running and we are going to turn hard over to starboard.
You may wonder why when it’s in forward, that the boat requires a lot larger radius to turn, than in exercise #1. That’s because the thrust is now on the inside of the turn.
When it comes time to approach your dock and turn within a narrow harbor, keep this in mind; so that you allow enough space to negotiate the turn, you must make in the harbor.
Thus, it is better to turn with the running motor on the outside of your turn.
Exercise #3 and Exercise#4
Repeat #1 and #2 with the other (port) motor running.
Lessons for In the Harbor
Once you are comfortable with all four exercises in the open water, repeat all four in the confines of the harbor.
Then, when you can do that without problems, it’s time to approach the large gas dock or service dock. Do it here, because there is more space and fewer boats than in and around you slip, and you may even have a dock helper. In this case, dock helpers may come in handy.
Have your lines and fenders ready with your First Mate on the aft corner with the dead motor, ready with the FLIPP Line, as described in each of our Introductory Docking Lessons.
Approach the gas dock with the shutdown engine closest to the dock. Regardless of drive system, forward gear will swing the bow in—not away; then reverse gear will draw the transom in—not away. (Depending on drive system, the wheel position is different as explained above in Exercise #1)
Docking without one motor is a unique situation; but, as sure as it is going to rain on your holidays, at some point, you’ll lose a motor. You may lose it while cruising, which will give you time to prepare and/or worry. You may lose it while docking. Now what? No time to prepare or panic, just react!
Regardless which twin engine drive system you have, it will someday happen to you. There’s a 50% chance the motor that stops will be the one that drives the power steering pump, resulting in Double Trouble.
Being prepared, by practicing this free lesson ahead of time, will get you out of trouble and save the day.
Accomplish the impossible with advanced information and practice.
Please report back when you mission is complete and let us know how it went.
Have fun with your mission.
More Tricks and Tips for Docking
In each of Dawson's Advanced Docking e-Lessons for Twin Inboards, Twin Sterndrives and Twin Outboards, there are detailed instructions on docking with the live motor to the dock and docking with the dead motor to the dock. There are many other neat maneuvers like the gas dock shuffle, pivoting on a piling included in the Advanced e-Lessons as well.