Twin rudder manouvering

[mobeydick]

On a boat with twin rudders (such as a Southerly) what is the best way to leave a finger pontoon backwards? (two people onboard)

Generally, with a single rudder, I would:
1. - rig a forward spring and a stern line to the pontoon;
2. - hold the boat in forward gear with helm to starboard, using prop wash over the rudder to hold the stern against the pontoon;
3. - Release stern line, send crew forward to standby the spring (boat not moving yet, so plenty of time)
4. - Engage reverse with a bit of starboard helm and/or let the spring tension pull the boat back/bows in (so stern out)
5. - reverse out clear of pontoon

Without the propwash in step 2, and no forward movement, would not the stern tend to drift out, making the boat uncontrolled when the stern line is released?

Thanks
MD

 

[aowen]

Twin rudder manouvering in tight marinas can be tricky which is why most Southerlies have bow thrusters. This is an optional extra on the boat but virtually essential for slow speed manouverabiity. If reversing from a finger pontoon was an issue I would spring the stern out and blip the bow thruster to take the bow away from the pontoon. Once underway she will behave like any other boat albeit with a slightly bigger turning circle.

 

[johnalison]

Speaking with all the authority of someone who has never tried to manoeuvre one of these craft, I would expect that backing out of a berth was likely to be easier than turning in tidily. I seldom need to go through the rigmarole described by the OP and usually just let the boat settle into a convenient attitude, either by pulling a bit on the lines or letting the wind do the work, and then charge out. With a slight prop-wash even from my saildrive, it is sometimes necessary to give a sharp burst in astern and knock the lever into neutral to turn the boat the way I wish, and I would expect twin rudders to behave similarly. Going ahead would be a different matter.

 

[Plevier]

I have a 32ft twin rudder boat and no bow thruster. My berth is alongside a pontoon with other boats close ahead and behind and I have to leave it going astern - ahead is closed off. It's quite a narrow channel between the pontoon and shore.
My standard method is swing the stern well out by motoring against a bow spring and a big ball fender then go astern vigorously. The first few seconds are always a bit anxious if it's windy!
(Vigorously because it is vital to get rudder control ASAP.)

 

[pete]

I bought a twin rudder boat last year and apart from the manoeuvring in tight spots it's great and as I keep it on a drying mooring it's not a problem but I am not in my comfort zone if I call in to a marina and am still learning how to control it. In almost windless conditions recently I tried to reverse out of a tight finger pontoon to starboard and after around 10 tries at shunting back and forth without gaining any angle I gave up and turned the stern to port and although I had to reverse the full length of the marina I did it first time without any problem. My problem was the prop walk was countering the turn. and by the time I was gaining a bit of steerage way I had to stop as I had reached the boats across from me and go forwards again. Glad it wasn't windy though.

 

[FullCircle]

I have a 32ft twin rudder boat and no bow thruster. My berth is alongside a pontoon with other boats close ahead and behind and I have to leave it going astern - ahead is closed off. It's quite a narrow channel between the pontoon and shore.
My standard method is swing the stern well out by motoring against a bow spring and a big ball fender then go astern vigorously. The first few seconds are always a bit anxious if it's windy!
(Vigorously because it is vital to get rudder control ASAP.)

Correct answer. Note that putting the helm over before you start moving achieves nothing except frayed nerves. It also helps to go astern straight up to 2kts, then throw it into neutral, then turn hard, applying astern again when it is turning.
In windy conditions, I have zig zagged sideways up the middle of the pontoon channels until I make my escape at the end where there is room to get the bow round.
Sometimes I have to reverse all the way out of the marina.
You get used to it. I have a sun odyssey 35, which has the added non bonus of a longish keel also preventing turning.

 

[mobeydick]

Correct answer. Note that putting the helm over before you start moving achieves nothing except frayed nerves. It also helps to go astern straight up to 2kts, then throw it into neutral, then turn hard, applying astern again when it is turning.
In windy conditions, I have zig zagged sideways up the middle of the pontoon channels until I make my escape at the end where there is room to get the bow round.
Sometimes I have to reverse all the way out of the marina.
You get used to it. I have a sun odyssey 35, which has the added non bonus of a longish keel also preventing turning.

I forgot to mention, I was talking about a 40ft+ boat. I would prefer to keep it under control at all times, using the method I described in the original post, but it sounds like the only way is to start reversing as soon as I release the stern line - and fast, until I get the rudders to grip. And hope the crew does not have a problem moving from stern to bow! A bit un-controlled in my opion, but I dont see any other way.

Thanks for posts

MD

 

[FullCircle]

I forgot to mention, I was talking about a 40ft+ boat. I would prefer to keep it under control at all times, using the method I described in the original post, but it sounds like the only way is to start reversing as soon as I release the stern line - and fast, until I get the rudders to grip. And hope the crew does not have a problem moving from stern to bow! A bit un-controlled in my opion, but I dont see any other way.

Thanks for posts

MD

I don't crash very often......

 

[mobeydick]

I don't crash very often......

No, but you have to admit, as soon as you let go the stern line, you have no control until the rudder bites. 9 times out of 10 OK, but things can go wrong, espacially with cross-currents or wind.

Also, the Southerly may be in a shallow berth, with its keel part raised, so not much keel to aid directional stability.

The reason for the original post is that, being 'between boats' at the moment, I am delivering/chartering yachts and do not have the 'feel' of them when I take them out for the first time. Hence I like t0 have a bomb-proof technique for the first manouver, at least!

MD

 

[Cardo]

Bow thruster every time.

 

[pteron]

On the Southerly 38 I recently sailed, I used a forward spring to bring the stern out against a fair old wind that was blowing us on, no problem. A burst of astern on the throttle had us out into the channel fine. It does have a bow thruster but was not necessary for this manoeuvre.

 

[Plevier]

No, but you have to admit, as soon as you let go the stern line, you have no control until the rudder bites. 9 times out of 10 OK, but things can go wrong, espacially with cross-currents or wind.

True, but it's very brief, my experience is that it's the arrival that is more worrying than the departure! When you want to be slowing down you have to keep speed on or you have no steerage.
Didn't do at all well arriving in my tight space on Sunday night in the dark with following tide and wind blowing off the pontoon
Had to come alongside the boat behind and grab it while crew got off with ropes to walk the boat in in the end.