Calling all Oyster 435 owners/sailors

[rwoofer]

It could be because Lechwe is a shoal draft (only just spotted that) and ours are deep keel. Certainly Hana is great in reverse with Max-prop, which is why I never bothered with a bow thruster despite going every year to france with its tight marinas and small pontoon fingers.

The only marina that I struggled with was Minimes in La Rochelle where Hana was longer than the width of the fairway and I had to reverse in. I still did it, but needed the harbourmaster to help me get out which suggests she turns tighter in reverse than forward!

 

[ChrisE]

I was being a bit flippant, in reality we can back into and out of most spots. We have a brunton and, as you suggest the trick is to line up the angles before attempting to manouvre. Also as tome says, giving the boat some reverse then easing off allows the boat to manouvre opposite to the considerable propwalk.

And as for proper boats, would yours have rolled off a rock with nothing but superficial gelcoat scratches, when whacked at 6 knots, as a delivery skipper proved for us last year? You young whipperysnappery types, I dunno /forums/images/graemlins/smile.gif

 

[jimbaerselman]

To answer the original question . . . It’s a matter of directional stability.

Your Oyster, (and many other vessels designed for long distance cruising) have a lot of directional stability. That is, they’re designed to have a strong tendency to maintain their course after some disturbance (a wave, a heel due to a gust). This means the autopilot (or helmsman) does much less work than on a less directionally stable boat.

The downside is that when you’re going backwards, the boat would prefer to point the way it’s travelling. So after a small disturbance, it’ll try to swivel around – to the degree that you can’t stop it swivelling once you get past quite a small rate of turn. Bit like balancing a pole on your finger . . . easy with a long pole, as long as you make lots of quick small corrections. But once you go past a critical angle . . .

The mechanism which creates this directional stability is the relative position between the boat’s centre of gravity, and the centre of lateral resistance caused by its under water profile. Think of a dart – all the weight at the front, all the aerodynamics at the rear. And you can’t make a dart fly backwards . . . it’s directionally very stable.

Boats that are easy to steer astern have little or no directional stability. Snag . . . the autopilot/helmsman has to work much harder to steer the boat forwards (though most owners would deny this – their own boat is always perfect!)). Just watch the helmsman’s activity on a more manoeuvrable boat running downwind in some waves . . . and see how difficult it is to set these boats up to self steer.

So, how do you steer backwards?

The first answer is ‘don’t’. When Med mooring, always go in bows to with a stern anchor!

The second answer is to practice a technique of using short bursts ‘ahead’ with lots of helm (while going astern) to create heading changes. Lots of winding the wheel activity here! Practice by finding a pair of buoys and doing figure of eights around them while pointing in one direction . . . you’ll soon find that (when going astern) all you have to do is initiate the turn, then immediately reverse helm to check it from building up (balancing that pole). And it’s all easier if you’re lucky enough to to have the bows down wind.

The third answer is a bow thruster. Not my cup of tea . . .

 

[demonboy]

Jim,

Just read your answer out to Queenie. It is extremely comprehensive and makes a lot of sense. Thank you for taking the time out to answer. Practising the figure of eight trick is a great idea, we'll be sure to give that a go.

 

[jimbaerselman]

Start with just a longish trip astern in the clear at about 1 - 2 kts. Then work up to an orbit around one buoy, then tackle the eight.

You'll find one direction is very difficult, if not impossible, due to your stern kicking port when revving astern.

I had a great (and very frustrating) day doing this many years ago when I first bought the boat. Worth it though . . . I remember a motto which has served me well - "learn to test, test to learn"

Enjoy!

 

[jhr]

Mainsheet looks a bit slack. /forums/images/graemlins/grin.gif

 

[Robin]

/forums/images/graemlins/smile.gif I was being even more flippant...

But we have a hull laid up with Kevlar a la bullet proof vests, ideal for bouncing off rocks (I'm told).

 

[ChrisE]

PM for the name of a skipper who'll try it out for you /forums/images/graemlins/smile.gif

 

[KellysEye]

Jim, we have a long keeler and struggle at times in reverse. That's the best explanation of the 'physics' behind the problem that I have ever read. Thank you.

 

[wingdiver]

Just to add my bit -

Last year, when mooring stern to, we had a devil of a job making our boat go where we wanted astern. So we fitted a bowthruster (and for better manouverability in tight spaces).

You can almost forget the wheel and use the thruster instead.

In fact, folks round these parts tell of brand new Oysters being reversed out of the lift dock before any wheels have been fitted and being berthed that way.

By the way, we fitted a Side Power hydraulic one - no power loss, short bursts, long cable runs.

Cheers

 

[Richard10002]

[ QUOTE ]
It could be because Lechwe is a shoal draft (only just spotted that) and ours are deep keel.

[/ QUOTE ]

Rogue is also shoal draft. I am currently in a marina in puerto Andratx where the fairway is narrow, (just > than LOA), and I had to reverse in against the prop walk, and with a cross wind pushing the bow to starboard. Found the bowthruster very useful, and got in without doing any damage to anything or anyone!

I dont think lechwe has a bowthruster.

 

[Koeketiene]

[ QUOTE ]
So, how do you steer backwards?

The first answer is ‘don’t’. When Med mooring, always go in bows to with a stern anchor!



[/ QUOTE ]

I've always found this safer too - no chance of rudder damage

 

[BlueSkyNick]

[ QUOTE ]
I dont think lechwe has a bowthruster.

[/ QUOTE ]You dont think correctly.

You are right, it is down to practice and confidence, but its the wind on the bow which causes the most problems.

I like JimB's idea of practicing in a figure of 8 - just need to find a couple of buoys a mile apart and five miles off the coast, to start with !