Steering trouble

[MarcGG]

Hi there!
Recently bought a pocket cruiser. A Steber 2200, here is a link to one identical to mine that is for sale and has photos of the hull out of the water.

https://www.boatsales.com.au/boats/details/2006-STEBER-2200/OAG-AD-16483811/?cr=1&psq=((Service=[Boatsales]&Make=[STEBER])&(((SiloType=[Dealer used boats]|SiloType=[Dealer new boats])|SiloType=[Private used boats])|SiloType=[Demo and near new boats]))&pso=0&pss=Premium

What I am trying to understand is why does it pull to port so much.
The rudder's shaft is not at the edge of the blade but rather a bit inside. Would that be the reason?
Whatever the case, can you also venture a solution? It is very annoying.

Your replies are appreciated.

 

[Mr Efficiency]

Might be an idea to contact the builder if still in business, although the rudder might not be an original fitting. Hydraulic steering might be needed to fix the problem, if you can't balance it.

 

[kapnD]

Single engine?
Big prop?
Steering system sloppy?
List ?
Pics or drawing of rudder?

 

[rwatson]

Thinking out loud here, the prop rotates in the direction of the arrow ?

That would try to push the stern to the Right of the picture from propwalk ?
That would make the boat try to go to port ?

The stern ends in a flat hull ( no V section) making the stern easier to deflect ?

A larger rudder would be my first instinctive thought.

Might be missing something ......

 

[MarcGG]

Thank you for you replies.
Yes, the prop rotates clockwise looking from behind the boat, and the boat pulls to port. Yes, single engine, big prop, not sloppy steering, no listing.

However, and after using the boat for a while, I learned that the speed is best when kept at 1800 - 2000 rpm and my attempts at going at wot with this little 50hp diesel was foolish. The bow goes up, and the speed only improves slightly and it is only then that the steering pulls badly to port.
At 1800 or 2000 rpm all is good.

Which brings me to another question for you good folks.

I live on a tidal river, meaning I have a 1.5m variation in the water level every 6 hours and a bit.
6 km away our river flows into a larger one that can be navigated at all times. Our little tributary, is rather shallow during low tide and my pocket cruiser has difficulty to pass some of the sand banks that are in the way. of course one can plan the departure but sometimes it is not easy to plan the return, and the last thing i would like is to be prevented from returning and having to wait for hours for the incoming tide.
In one occasion that I was facing low tide coming back, I had passengers and I asked them to go into the stern cabin to lift the prop. This actually worked a treat and the boat levelled very well with just one (small) adult and two little kids, not even 100 kilos in total. My depth sounder, if it is to be believed, was screaming alarm at 0.7m but i kept on going with as low as occasional 0.4m without the prop hitting anything.
So ... this got me thinking. Could I replace those fix (pathetic) tabs I have in the back for some proper and larger variable trim tabs to give me some lift in the stern and ... install a ballast water tank in the bow for the times I face low tide and have no one to shift to the front? I know sailing boats have water tank for ballast they pump full and empty at will for a different purpose. Is this idea feasible or out there? What about larger and variable trim tabs, do they work at my relatively low speed ... probably 7-8 knots at best?
Your reply is appreciated.

 

[gonzo]

You can add a trim tab to the rudder. It is a small flat vertical piece at or near the trailing edge. You bend it to counteract the turning force until the wheel becomes neutral.

 

[kapnD]

The pointy end of the boat is commonly referred to as the bow, and the other end, the one with the wake behind it, is the stern.
Trim tabs normally help keep the bow down, but do little to raise the stern, and are only effective at speed.
I usually take along a couple of plump wahine to help trim the boat!

 

[rwatson]

"I had passengers and I asked them to go into the stern cabin to lift the prop"
"install a ballast water tank in the stern"

I'm confused - it sound like you are trying to put weight in the stern to raise the prop ???

I would have though weight in the bow ??

 

[MarcGG]

Ha ha ... yes, I want to lift the back and lower the pointy bit.
Any useful ideas?

 

[MarcGG]

Nothing?

 

[rwatson]

Like I said
"I would have thought weight in the bow"
after you said
"install a ballast water tank in the bow"

 

[Mr Efficiency]

If you want the bow to fall, slow down to a minimal wake kind of speed. Tabs will be pretty useless at the speeds you are talking about.

 

[fallguy]

A forward water tank is a great idea if you have the space.

Isn't your rudder the ultimate low point?

You could also devise some means of raising the rudder to a less effective, but shallower draft as well. Just an idea. Most sailing vessels like to hang up at landings n such and pulling the rudder up is sometimes needed in real shallow situations.

Perhaps a high position pin might work.

If the keel is the low point; another idea would be inflatable sponsons; what a pita.

 

[MarcGG]

The keel is the lowest point. From the few times we did this at low tide, shifting weight to the bow works to lift the prop and push the vessel through. The speed of the boat when in shallow water is of course minimal, engine at 1000 rpm and just enough to go forward. The speed of the current is high so can not navigate at very low speed or would go backwards. Water goes easy 2 knots.
Seen a few of this ballast tanks complete with pump and switch and levels and what not. I wonder if I can use the same connection the motor uses for cooling so that I don't need to drill another hole? For emptying the tank I could use the same place the bilge pump uses?
Your replies are appreciated.
M
PS
Watson, you are a funny guy ... English is my 5th language so nautical terms tend to get mixed up in the melon

 

[fallguy]

You can use the same raw water intake for such business.

But the drain might require some thought or a new thru hull and manual plug.