Twin Sterndrive close quarters advice

[ari]

Firstly, ignore any advice about leaving the wheel amidships and just using the engines. Works for shaft drive but sterndrive just doesn't have the leverage (as props are effectively behind the boat) so it will work to some extent, but you really need to use the wheel as well to direct the thrust.

Now imagine you did have the wheel amidships and went astern on the port engine. Because it's pulling the port side of the boat more as is on that side, it will gradually swing the bow to port.

Now imagine putting the helm down to port as well, now you have some thrust to the side at the stern pulling the boat to port from the propellor.

So both in conjunction will gently crab the boat to port as it goes backwards. Find the right amount of helm (and it will vary depending on things like wind) and the boat will remain parallel to the berth but easing to port as you move backwards.

You can also slow things down by shifting to neutral , putting the helm down to starboard and giving a nudge ahead on the starboard engine (same sort of thing applies, the fact that it's the starboard engine will 'lever' the bow to port, the fact that the helm is down to starboard means that the thrust from the outdrive will push the stern to port).

Bear in mind we're not talking full lock here, nothing like. You need to experiment to find out how much.

 

[SC35]

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.

This: the wheel does need to be pointing in roughly the right direction with stern drives as the point of thrust is aft of the transom.

It will vary according to the boat, but I usually apply half a turn one way or the other about the centre position when docking.

 

[Elessar]

This: the wheel does need to be pointing in roughly the right direction with stern drives as the point of thrust is aft of the transom.

It will vary according to the boat, but I usually apply half a turn one way or the other about the centre position when docking.

That doesn’t contradict what I said - don’t understand the comment.

 

[SC35]

That doesn’t contradict what I said - don’t understand the comment.

Something that doesn’t happen often on the forum, it’s someone agreeing with someone else

 

[Elessar]

Something that doesn’t happen often on the forum, it’s someone agreeing with someone else

Fair point. No wonder I was confused.

 

[Meagain]

Interestingly the different views and approaches used, which suggests there is a lot of trailing to see what works best for you and your boat / berth. You don’t mention prevailing wind/tide as this will influence bow. For me I have twin stern drive and berth with neighbours boat as per your diagram. I use the outside engine only (in this case starboard) direct the drive as you have drawn (rarely full lock) and always small nudges. As per earlier post aim to get the stern in early (about 1 meter in form end of pontoon), allows crew to step off attach a mid rope which is a set length to stop going too far back! This allows them to “walk the stern in”. Reality is that once the stern is in at ~ 1 meter, then steering is moved to a more neutral position for rest off manoeuver still using the outside/starboard engine pulls the bow parallel to the pontoo. I seem to rarely need the bow thruster this way (however as per other posts, don’t be proud get one and use them!!).
Final again per earlier advise
steer then gear
nugdes only
go slow
fenders are your friend.

 

[Elessar]

Interestingly the different views and approaches used, which suggests there is a lot of trailing to see what works best for you and your boat / berth. You don’t mention prevailing wind/tide as this will influence bow. For me I have twin stern drive and berth with neighbours boat as per your diagram. I use the outside engine only (in this case starboard) direct the drive as you have drawn (rarely full lock) and always small nudges. As per earlier post aim to get the stern in early (about 1 meter in form end of pontoon), allows crew to step off attach a mid rope which is a set length to stop going too far back! This allows them to “walk the stern in”. Reality is that once the stern is in at ~ 1 meter, then steering is moved to a more neutral position for rest off manoeuver still using the outside/starboard engine pulls the bow parallel to the pontoo. I seem to rarely need the bow thruster this way (however as per other posts, don’t be proud get one and use them!!).
Final again per earlier advise
steer then gear
nugdes only
go slow
fenders are your friend.

We don’t get off out boat until we are tied up. Lasso that mid line.
The WAFI leap and wrangle approach is so dangerous. Schools even teach it which is crazy IMO.

 

[Momac]

I would not claim to get it right 100% if the time.
But we come into a mooring with no drama, (no panic, no arguments). If we have to start again also no drama.
It was not always so.

A good chief officer is worth their weight in gold.

 

[Elessar]

I would not claim to get it right 100% if the time.
But we come into a mooring with no drama, (no panic, no arguments). If we have to start again also no drama.
It was not always so.

A good chief officer is worth their weight in gold.

Good advice. Never hesitate to try again. There is no shame in it. My record is 12 attempts, being watched by race entrants at Poole yacht club.

Also never be ashamed to go to an easier berth to await tide/wind changes.

 

[Momac]

Also never be ashamed to go to an easier berth to await tide/wind changes.

I did that once
Informed the marina we would return when the wind dropped , which we did.

 

[rafiki_]

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.

I never used the hand wheel on my twin sterndrives for close manoeuvres, but you are more competent and experienced than me.

 

[Elessar]

I never used the hand wheel on my twin sterndrives for close manoeuvres, but you are more competent and experienced than me.

Stern drives have much less of a turning vector than shafts because
1 the props are further back
2 the props are closer together
Plus generally
3 the props are smaller (less prop walk)
4 duo prop (no prop walk)

You can increase the turning vector on shafts by about 30% in forward gear only by using the wheel but you’d be in extreme conditions to need this as you got a lot of turning capability on the sticks alone.

But with stern drives the turning vector is much less to start with and massively increased in both forward and reverse by using the wheel. It doesn’t take much of a breeze or tide for this to be necessary.

Not properly learning to use the wheel is why some people say stern drives are harder to handle. They are not. They are just very different.

 

[rafiki_]

Stern drives have much less of a turning vector than shafts because
1 the props are further back
2 the props are closer together
Plus generally
3 the props are smaller (less prop walk)
4 duo prop (no prop walk)

You can increase the turning vector on shafts by about 30% in forward gear only by using the wheel but you’d be in extreme conditions to need this as you got a lot of turning capability on the sticks alone.

But with stern drives the turning vector is much less to start with and massively increased in both forward and reverse by using the wheel. It doesn’t take much of a breeze or tide for this to be necessary.

Not properly learning to use the wheel is why some people say stern drives are harder to handle. They are not. They are just very different.

Mine were Merc outdrives so not duoprop. The Sunline responded very well to the props. Easy to pop in and out of drive. Worked for me, but I have no experience of duoprop stern drives.

 

[Elessar]

Mine were Merc outdrives so not duoprop. The Sunline responded very well to the props. Easy to pop in and out of drive. Worked for me, but I have no experience of duoprop stern drives.

Bravo 2 mercs have big single props so do have propwash. Nearer to a shaft feel than most outdrives.
Props still further back though and still beneficial to use the wheel but starting from a higher base.
Eg when stern to use engine nearest the pontoon, steer slightly towards the pontoon and you will motor forwards whilst crabbing sideways away from the pontoon and so not rolling fenders out.
Engine only and you have to use the engine furthest from the pontoon and use the bowthruster to get the bow away.
Both work and ultimately the one you are comfortable with is best.