sterndrive and sternthruster together ? Germany needs help !

[PCUK]

Fitting a small keel or skeg right under the transom just ahead of the outdrive will dramatically improve slow speed manoeuvring as it acts as a fixed rudder. I have fitted them on several boats, just bolting through the hull into a plate inside. All made of mild steel and epoxy coated, so very cheap! They have no adverse effect on high speed running and also help to protect the outdrive from impact damage. Far cheaper than a stern thruster but I seem to be the only one in the UK to regularly use this method of improving outdrive handling!

 

[Julia-Kristina]

Fitting a small keel or skeg right under the transom just ahead of the outdrive will dramatically improve slow speed manoeuvring as it acts as a fixed rudder. I have fitted them on several boats, just bolting through the hull into a plate inside. All made of mild steel and epoxy coated, so very cheap! They have no adverse effect on high speed running and also help to protect the outdrive from impact damage. Far cheaper than a stern thruster but I seem to be the only one in the UK to regularly use this method of improving outdrive handling!

Thank you for your advice. Can you put a photo here? I can not imagine exactly where you fitted this keel and I am very interested to see that. Could I also fit it to a glassfiberboat ( our boat is n o t made of steel ! )

I already had installed something very pracitcal , a so called "course-keeper ".

Here you get informations about that : http://www.course-keeper.com/

This is a wonderful invention that I can recommend - when I am going slowly with the boat it keeps its course as if it had a keel, like a displacement boat.

But as I wrote the problem is the wind : then even the course-keeper is not sufficient anymore.

Thank you and kind regards,

Julia-Kristina

 

[Si Dude]

Hello just come across this via a google surfing

I'm a Relcraft Sapphire owner in the uk, she's very similar design to yours but only 23ft long. I too suffer in strong side winds again due to the nature of the hull, only 3-5 inches sits in the water so I can believe they found space to fit a bow thruster.

The only advise to possible help with the bow thruster is to make sure the nose is weighted down, fresh water tanks full so there is enough depth for it to work.

Just out of interest what sort of engine does she have?

If your boat is anything like mine its only in very tight enviroment that a strong cross wide would cause any major problems.

visit my FaceBook page if you require any 1 to 1 Relcraft help

http://www.facebook.com/pages/Relcr.../pages/Relcraft-Boaters-Group/136903519685887

 

[Julia-Kristina]

Julia-Kristina to SI DUDE

Hello , thanks for your answer.

First of all : what does " cross wide " mean ???

To answer your question: it is a Volvo Penta AQ 211, has approx. 215 hp

And I also bought a second motor from Yamaha, an outboard engine which will be fixed at the stern as an additional help if one day the main motor breaks down ( I had this situation on my first trip with her, was not so funny . The fuel pump was broken.)

Of course I fill the water tank up as much as possible, it is more hygienic to drink water out of bottles anyway.

And I also bought ballast !

Little bags with metal remains, very small but heavy.

I will put the bags as far as possible in the front , behind the bow beds.
Cross your fingers that this will help !

( And if this is not enough my husband will be put on the bow as a figurehead, brings 80 kilos too )

And maybe a help for your boat if she is also not going straight ahead ( " to sheer " ? " To yaw ? " ) : I will also change some parts of my coursekeeper / ruddersafe .
This coursekeeper helps very much when you are going slowly. It was one of the best ideas for our boat, very recommendable.

It has two little "noses" which are lifted up automatically when the boat is going faster so it can glide better.

Since I want to go slowly I will abscise these little noses .
I was told that then the boat goes better straight ahead even with higher speed. We will see. Maybe an idea for your boat too ?

As I wrote I have already a bowthruster but it is not very strong.
I would like to have a sternthruster too.

Since you can not fix a normal sternthruster when you have an outdrive ( in German " z-Antrieb ", I did not find the exact translation ) I am now thinking about mounting a so called "jet thruster" , formerly produced by the netherland company willdo .

Maybe also this thruster would be an alternative for your boat which I think has the same outdrive system probably.

Did you see the photo of our boat in this thread ? On the photo she is unrenovated, during this winter she will be refitted and hopefully look really beautyful again

I will have a look on your link in facebook, thank you.

Kind regards from Germany,

Julia -Kristina

 

[Si Dude]

Wide was ment to be wind lol sorry the joys of using the forum through the iPhone. No I haven't had chance to look at your photo of her yet but very keen to find out how you may have got round some of the pit falls of refitting a boat. I too striped and refitted my boat out. After your last post I'll make sure I'll add them to the Facebook page. Hope you find the page interesting even in it's early days.

 

[Julia-Kristina]

Relcraft 29 again

Hello, nice that you answered so quickly.
I already published a photo of her about one hour ago on your facebook page. You find it on the left side, under the other photos.

You see the swans - that's her
She is still unrenovated, everything will be done in spring.

She is now lying in the north of Berlin, at a lake called Lehnitzsee.
I am living in Bavaria, in the north of Munich, so I can not go every weekend to the boat. And so it will take time until everything ist done. :-(


kind regards !

 

[PCUK]

Hello Julia,
Sorry for the delay in replying, Here's a photo of a skeg I made recently for improving straight line running at slow speed. It is made of steel and epoxy coated. Cost less than €100.
It is then simply bolted to the bottom the fibreglass boat at the stern just ahead of the outdrive through another steel plate fitted inside the hull for added strength.
You may need a larger skeg to help stop sideways drift.

 

[Julia-Kristina]

Thank you

Hello and thank you for your answer and the photo.

In Germany we also have a similar boat-Forum ( http://www.boote-forum.de/index.php ) and I already had asked for experiences with this construction.
But a relcraft boat is very seldom in Germany so I could not get any reports of experience with this type of boat.
There were some members of the forum who had made similar constructions but their boats were smaller and they wrote that the effects are not very strong.

Do you think this would really function also with a bigger boat?
Our Relcraft has about 29 feet length - don't you think the pressure of the water could be too strong and maybe even quarry out the skeg ?

Questions , questions...

I will show the photo of your construction to the shipyard where I will have done some works in spring.
I am very curious to hear what they will say !

If you have already made practical experiences with this construction just write about here - it is certainly also interesting for many people who are having the same problems.

Thank you again and kind regards from Germany !

 

[boatmaster]

Hello Julia,
Sorry for the delay in replying, Here's a photo of a skeg I made recently for improving straight line running at slow speed. It is made of steel and epoxy coated. Cost less than €100.
It is then simply bolted to the bottom the fibreglass boat at the stern just ahead of the outdrive through another steel plate fitted inside the hull for added strength.
You may need a larger skeg to help stop sideways drift.

Hi

There have been some very interesting responses here, I had experience in a birchwood 25 with identical handling problems because she wasnt heavy enough. The owner made a skeg just like this one and the transformation in handling was astonishing! I think you you would do well to try the skeg idea first as it will not cost too much money. if you are still not happy afterwards, the skeg can be removed with little work or left in place as a useful addition.

 

[Julia-Kristina]

additional skeg under a relcraft topaz 29 ft

Hi,

I am only worried that in case you go a bit faster or you do a narrow turn the pressure of the water may damage the whole construction ...

and how long do you think this skeg should be for a 29 ft. boat ?

Maybe you can have a look on the photos in my album that I just added, there you can see the hull when she was lifted over the trees.

Thank you to all of you for your advices.

Julia-Kristina

P.S. here the link to the German boat-forum - maybe interesting for all of you who understand a bit German ?

http://www.boote-forum.de/index.php

And photos are international anyway.

It functions in the same way as this english forum. You just have to register to see photos.

 

[mateyboy]

Thank you to all of you for your advices.

Julia-Kristina

P.S. here the link to the German boat-forum - maybe interesting for all of you who understand a bit German ?

http://www.boote-forum.de/index.php

And photos are international anyway.

It functions in the same way as this english forum. You just have to register to see photos.

Merci, pas de probleme!

 

[PCUK]

I have fitted one of these to a 31ft boat and it made a huge improvement. It won't affect normal handling and the Relcraft hull won't be damaged by fitting one. The plate on the bottom 'traps' water and adds to the sideways stabilising effect.

 

[Julia-Kristina]

Merci, pas de probleme!

Tiens tiens - est-ce que tu es francais ?

Malheureusement mon francais n'est pas suffisant pour avoir une discussion technique :-(
D'où viens - tu ?

Oder bist Du aus Deutschland, dann sollten wir uns lieber im deutschen Forum treffen ?

Anyway - thank you all for your help, I will keep the solution with the skeg in my mind, seems to be very interesting.

 

[Julia-Kristina]

I have fitted one of these to a 31ft boat and it made a huge improvement. It won't affect normal handling and the Relcraft hull won't be damaged by fitting one. The plate on the bottom 'traps' water and adds to the sideways stabilising effect.

This is what I also wanted to know:

1) what about the effects when you are going fast, more than 10 knots, and
2) what about the handling when you do narrow turns ?

Isn't here a negative effect concerning the strength you need to turn the steering wheel, since there is so much more resistance by the skeg ?

3) Our boat has a sterndrive ( " Z-Antrieb " ), one engine.

How much distance should be between the aft part of the skeg and the sterndrive / propeller ?

I am still thinking about also mounting an additional jet-thruster.
Do you have an idea how much space there should be between propeller - jet-thruster - skeg, all in one line ?

I wish you all a nice and sunny weekend,
and thank you all for your advices,

Julia - Kristina