Twin Sterndrive close quarters advice

[elrossco22]

Hi All, reasonably new to boating and looking for some advice on a particular situation. I have a twin sterndrive boat without a bow thruster and would like to know in the situation I've tried to draw in the diagram what engine I should engine in reverse. The situation in play below is that the boat is straight with the berth however a little too close towards my neighbours boat on the starboard side and as such I'd like to essentially move the boat to port with minimal swing of the bow. I've managed to do this before however now I've actually started to think about it I've confused myself with conflicting articles that talk about prop wash vs forces at work and now I can't remember what age I engaged in previous berthings to achieve this. Tia

 

[tico]

My experience with a 31' with twin outdrives is reverse on the inside (port) engine only with the drives in the configuration shown - gives reverse and a bit of movement towards the finger, but without swinging the bow.
Based on the leverage - Thrust line is close to the centreline.
Were you to go in reverse on the outer engine (Stbd) then the result would be for the bow to swing to the Right more.
Main things to bear in mind...
'Steer before gear'
'One engine at a time'
'Only go as fast as you would like to hit someone!'
' No shame in aborting and going around again'

 

[SC35]

errrk, boat shaped like a soap dish in diagram caused misinterpretation
although most motor boats do actually handle like a soap dish

 

[DavidJ]

Tricky one. You are not alone.
I have a bow thruster and still don’t get it right every time.
I find jabbing (nudging) one of the throttles with a turn on the wheel gives me the result I want “sometimes”

 

[petem]

You don't show which way the wind is blowing.
Assuming "not much" I would nudge the Port engine into Forwards which will knock the bow to the right a bit.
Then straighten up and nudge ahead on both.

Starboard engine in Reverse will also work, but you might end up going backwards depending on approach speed

Both Starboard engine in Reverse and Port engine into forwards at the same time will most likely result in fibreglass repairs.

If it's a duoprop, you can forget about prop wash.

Are you assuming wheel dead centre?

 

[ChromeDome]

Trial and error I'm afraid.

Find a calm spot somewhere and start exercising. Take your time and - repeat.

 

[SC35]

Are you assuming wheel dead centre?

OP diagram has "Wheel Hard to Port" as the initial condition.
Wheel probably needs to be a bit to Starboard.

 

[PCUK]

Trial and error I'm afraid.

Find a calm spot somewhere and start exercising. Take your time and - repeat.

It's the "How do you get to Cargegie Hall" conundrum. - PRACTICE!

If it were me I'd go half astern on port engine and slow ahead on starboard engine to keep boat attitude the same.

 

[jrudge]

Bear in mind in the real world the boat at this point is already moving backwards.

If the use the post engine in reverse it will pull the stern over and the boat will continue backwards. Given how boats are shaped your stbd side will eventually brush the side of the other boat - but that is why boats have fenders. Bear in mind on a med berth you touch fenders each time the boat moves unless you have a marina that allows more space than your boat which is rare so it is what it is.

I assume the boat is quite small to not have a thruster so if all else fails push it off. Consider getting a thruster. There are some purists who say never- but back in the real world with a cross wind the thruster makes life infinitely simpler.

If you then add in the wind and possibly tide you will have to adapt what you are doing to the conditions of the day - most likely in deciding when to turn into the berth and use the wind and tide to help solve the problem not create one. The faster you are moving the less drift. This is a statement of fact not a suggestion to go hell for leather but near in mind if you are very slow then the wind and tide will win.

Also find and instructor for an hour. They are mostly great people and will help you understand your boat.

 

[rafiki_]

I had a twin stern drive Sunline 31. When reversing into the berth as you show, I never used any steering wheel, purely the engines. And small amounts of reverse or forward, using the idling speed. You cannot go too slowly. You can never have too many fenders either.
Initially a quick burst of starboard reverse. Then port reverse to straighten. Then starboard reverse. Drift a little, and maybe a touch of starboard forward to straighten.

 

[Momac]

My chief officer stands at the stern and has a rope on the middle cleat and the rope outside of the rails.
I reverse up and drop her maybe a metre along from the end of the pontoon. Then she is on the pontoon with the rope on the middle cleat and can control the boat if required.
At this point I usually have the steering central and steer the stern over to the pontoon on the port side with reverse from the starboard engine or maybe forwards from the port engine.
Little nudges into gear and immediately out of gear seems to work best.
I do have a bow thruster but try to use it minimally but would nor really wan to be without the thruster (nor without the chief officer).

The other week I did go around a second time. The wind has been blowing the wrong way quite a lot this year .

But folks do it other ways and they survive.

You just have to find the method that suits you best.

 

[SC35]

okay, I have totally misread the situation, having a diagram with the bow as the pointy bit and I would have stood a chance

So yes, reverse nudge on Starboard.
Straighten up, reverse nudge on both.
Forward nudge on Starboard when in the right place to finish off.

 

[marcochi76]

 

[PaulRainbow]

I had a twin stern drive Sunline 31. When reversing into the berth as you show, I never used any steering wheel, purely the engines. And small amounts of reverse or forward, using the idling speed. You cannot go too slowly. You can never have too many fenders either.
Initially a quick burst of starboard reverse. Then port reverse to straighten. Then starboard reverse. Drift a little, and maybe a touch of starboard forward to straighten.

My first boat was a Princess 32, twin outdrives. I always manoeuvred close quarters with just the engines, with the wheel dead ahead.

 

[PCUK]

My first boat was a Princess 32, twin outdrives. I always manoeuvred close quarters with just the engines, with the wheel dead ahead.

God they were a hard ride in the rough and not so rough! Didn't like the way the bottom and floor boards flexed either.

 

[PaulRainbow]

God they were a hard ride in the rough and not so rough! Didn't like the way the bottom and floor boards flexed either.

Was interesting with any waves on the beam

 

[petem]

My experience with a 31' with twin outdrives is reverse on the inside (port) engine only with the drives in the configuration shown - gives reverse and a bit of movement towards the finger, but without swinging the bow.
Based on the leverage - Thrust line is close to the centreline.
Were you to go in reverse on the outer engine (Stbd) then the result would be for the bow to swing to the Right more.
Main things to bear in mind...
'Steer before gear'
'One engine at a time'
'Only go as fast as you would like to hit someone!'
' No shame in aborting and going around again'

I agree.

Best advice is to get a bow thruster ASAP.

 

[petem]

Personally, I think that any instructions that involves simultaneous ahead/astern and steering input is information overload for a beginner.

 

[BruceK]

If you use chrome browser this online simulation is great fun to get a grip on the basics but as all simulations will only give you an idea on whats best to use when and no replacement for actual real life scenarios and experience. Good fun nonetheless

The Boat Docker

 

[Elessar]

Find a long stretch of pontoon.
Reverse along it keeping 2m from the pontoon and parallel to the pontoon.

Use the wheel to position the back of the boat. (Steer left to move the back to the left. Not full lock. Move the boat sideways gradually)
Use 1 engine at a time.
Use the engine choice to position the bow of the boat. (Port engine pulls bow to port and visa versa).

It’s harder than it sounds.
When you muck it up go back to the start and do it again. And again. And again.

It will click and go into muscle memory. And then you won’t have to think about it. You’ll just enjoy your boat as you reverse into spaces as instinctively as you do in a car.

I don’t buy the don’t touch the wheel theory for outdrives. That’s for shafts. Outdrives (and IPS drives) are all about the wheel.