Aussie made 39' Ocean Trek with Levi Surface Drives

Hi HakimKlunker, thanks for the comment, I think you and DogCavalry are both correct in saying that the drives appear to be very simple in design, which I love because simple means less parts to break and less cost to repair if there is a breakage. Although I would imagine that the props for these things are a whole other story?
I guess I will have to see what it is like to reverse and then decide if I am going to make myself some "drop down" electric bow thrusters for docking.
Now that I know these drives are quite simple I don't think I will be considering any change in the drive system, especially due to the cost involved.
Thanks again.

 

Hi Bajansailor, Yes $150K is the reduced price, which is the top edge of my budget, I started looking around the $100K mark but then when Maritime Safety said I could put anything up to a 12M boat on the mooring I kept lookin and somehow it just snowballed I am curious though, I didn't realise that on a displacement yacht like this, that you could just put bigger motors and drives in to overcome the "hull speed" formula, what size would you have to go to, to climb over your bow wave to achieve this?

 

Rudi had a small production with a partner in Penang, Malaysia. But they separated and he later registered a trade in Germany, where illness struck him too fast to set up something lasting.
He was a mellow and humble man.
If you don't get anywhere elsewhere, I can offer you to reverse-engineer spares that you can't get any longer.

 

Thank you @HakimKlunker . I have wondered what happened for years.

 

Why did you ask?

 

The conventional 'hull speed' formula (which is approx 1.3 x square root of waterline length) applies for 'conventional' displacement hulls, ie those which have a length / beam ratio around 3.

The hulls of that Simpson cat probably have an L/B ratio around 8 or maybe 10, and because they are so much skinnier than a hull with L/B = 3, then they can go faster than the conventional hull speed formula.

The hulls of the cat in my avatar photo have an L/B ratio of approx 15 at the waterline, hence they are still effectively in 'displacement' mode (ie they are not planing) when they are doing 20+ knots.

William Froude started everything off in the late 1800's when he was researching resistance - he started by towing a plank (vertically on edge, not horizontally) in his homebuilt towing tank, and later progressed to towing scale models of vessels.
William Froude: the father of hydrodynamics https://rina.org.uk/industry-news/maritime-history-and-heritage/william-froude-the-father-of-hydrodynamics/

 

Hi BlueBell, Sorry I didn't get back to you earlier, I have found that there is a lot of information about how fast/efficient the surface drives are, but very little info on their manoeuvrability at low speeds.
The comment on the advert for the boat by the owner said that "there is no need for bow thrusters, she turns on a dime", but if there is one thing I have learnt from working in the marine trade, I'd trust a guy whose selling a second hand car more than I'd trust a guy who is selling a second hand boat.

 

Thankyou bajansailor, I have read articles on Froude's formula but it has never been explained as well as you just did, I had no knowledge of the L/B ratio affect on the formula.
Cheers.

 

Some great info there 2REOV8, I've scrolled past that listing but didn't realise it had surface drives though. The fitout looks pretty spacious and comfy. From the info those drives do look pretty simple, Vesconite bearings etc..
I've seen one across the river when visiting Mackay a couple years back. All the best with it.
Jeff.

 

Thanks Jeff, I'm flying down this Tuesday to have a look, should be interesting, I have been looking for a while but you just can't tell from the pic's on the net. I'll let everyone know how it goes. Cheers.

 

True, we looked at a Markline 11M listed with Glenn a couple months back. He has a background in tv so has presentation skills in vid and pics. That Markline boat was cheapish but needed some work. Unfortunately the day we looked it was very rainy.
Jeff.

 

Hi Jeff,
Sorry for not getting back to you sooner, it took me a while to get over the shock of seeing that boat. I think, just like your Markline experience, this company has a few "Mooring Minders" on their books. I have never been so disappointed, the videos and pictures that were on the add are nothing like what the boat looks like now, I think the add was from when it was sold 3 years ago and it has been left to rot on the mooring. The flybridge didn't even have a bimini anymore and the clears were just left hanging half over the instruments, one motor couldn't be started, the steering didn't work, the forward deck, the cockpit, and the rear of the flybridge floor all flexed badly when walked on and there was a lot of internal water damage from previous leaks. It was a complete and utter waste of time and money after I had been told "it just needs a bit of a clean cause it has only been used twice in 18 months". So, lesson learnt, you need to see current date stamped pic's before even considering to look at a boat, especially when it is so far away, the whole debacle cost me a day and $500 worth of airflights and car hire. On a positive note, I really do appreciate everyones input and info on the boat, and hopefully something else, in much better condition, will come along soon. Thare are a few pic's of the condition of the boat below.
Cheers until the next one.

 

That is a shame to find out the true condition of the boat after going to so much time, effort and expense to go and have a look at it.
It can't be very good for those Arneson drives to be covered in weed like that - I guess the boat has been in the water a long time, and there are probably doubts as to if there are any zinc anodes on the Arnesons.
There are more power cat fish in the sea - Oz does seem to be happily cat crazy - so I hope that you can find something much better soon.

 

take out a very large bank loan for jets

 

The Markline we looked at is sold now so suited someone, the advertising said owned by marine engineer and by same family for 25 years, when we looked, stb engine turbo partially dismantled. Most rang true but certainly colored for best impression. One of the photos represented the transom anode wasted & painted over, may well have been a new yardy worker, may well have been replaced with new after the pic taken. Still on the lookout for a cruiser
Lots of unloved boats available, my current yacht too, just putting some time in to tidy up for summer, found it had been run into 2 days ago,.. something else to fix, 3 x stanchion bases and cracked and bruised teak toerail.
All the best in your search.
Jeff.