Building a catamaran for both river and sea

[iuliradu]

First of all I want to greet everybody and say that I appreciate and share your passion for boats. I drive small boats and speed boats ( 5-7m, 20-80hp) since I was a child.

In the last period, I was charmed by catamarans, and the ideea of building one haunted me day and night. As my father share some passion for boats we decided to build one together.

We live near the Danube River and Danube Delta, in Romania, and because of this we want to build a cat that is suitable both for sea sailing and in the same time capable to navigate on the river ( cut-watering way, ascenting).

Atfer researching a couple of days on the internet I found this forum, and I think that is a starting point where we can ask for advices enthusiast which maybe somethimes they where in the same situation like us. We want to build a cat up to 8-9 meters, able to host 4 to 6 persons, and light enough to navigate on the river powered by engines and in the same time safe enough to sail on the Black Sea.


My father build in the last years 3 pontoons - floating hotels - approximately of 30 meters lenght each (made by steel) and I can proudly say that he have some experience in this area - even building a wood catamaran is not the same thing, there are some overlapping knowledges.

I found some website where you can buy plans, one I liked is Roger Simpsons. Before I decide what kind of plans should I buy, I need to be fully sure that this is what I need, so I'm asking all of you if you have and knowledges if the kind of cat suitable for both river navigation and sea sailing.

I'm looking to buy plans for approx. 1000$ and if you make and recommandations of designers who have such kind of cats i'll be fully grateful.

iulian radu

[gonzo]

I think that your best bet is to talk to the person that designed those floating hotels. You already have a working relationship, which should help.

[iuliradu]

Originally Posted by gonzo

I think that your best bet is to talk to the person that designed those floating hotels. You already have a working relationship, which should help.

Thank you for your reply Gonzo. Sure I asked those ones who make designs, but more than these I'm asking your opinion, especially for those ones which maybe where sometime in the same situation like me.

I'm also asking you if you know designers where I can buy plans, as I'm trying to find as many plans as possible, in order to achieve an overview of the offer and to be sure I found some plans which fits as much as possible my needs (as regarding functionality and design, costs).

I'm asking any of you who use a cat for both sailing and river navigation and if you have any documents and guidelines ( or even pictures) of cats build with this purpose in mind.

[Deering]

Depends on many factors. What's the depth of the river? If it's shallow, then you'll want a cat design with retractable dagger boards rather than fixed keels and rudders.

Sailing cats are generally quite beamy. Rivers are often narrow and crowded. Running a cat up the river to moor it is one thing. To use it to regularly navigate around the river's another.

[troy2000]

I was completely unaware that the Danube Delta existed, until you started this thread. I've been reading up on it, and the subject is fascinating.

Are you really sure you want a catamaran? Although one would be quite practical in the ocean and the Danube itself, it seems to me that narrow, shallow and twisting delta waterways would be better served by a shallow-draft monohull with a retracting centerboard or leeboards -- particularly if you want to get off the beaten track, instead of just following the main traffic arteries.

[specmar]

Here is a brand new design intended for operation on the US Colorado river and lake Havasu. Boat is compliant with ABS and USCG small passenger carrying vessel. Welded aluminum construction, Scania Diesels, Hamilton water jets. Projected top seed 40 knots. If interested, contact Edgar Van Smallen at edgar@brebv.com.

[Wavewacker]

Specmar, I can't download a pdf, wonder if you'd mind describing the beast. Just saw a TV report on the subject, they were in what looked like a perow, I may have misspelled that, that cajun boat used in our southeastern swamps.

[specmar]

The boat is 14 meters x 4.5 meters and is designed to be cut automatically by computer controlled machines. Pre cut-parts can be provided from the Netherlands. This is a very efficient method of construction, reducing man hours to construct the hull by a considerable margin. Boat is fitted with a hydro-foil between the hulls to greatly reduce fuel consumption. Designed to comply with ocean sea conditions.
We presently have a number of our mono hull designs under construction and operating on the Black Sea as high speed police boats.

[Wavewacker]

Wow, would be very nice in aluminum! My garage is not that big. Someone put a hydrofoil between the pontoons of a pontoon boat with a V8 I/O, performs like a deck boat (almost....got to watch what I say here, lol)

Wonder what the draft is, I was thinking the OP would need a much smaller cat, like a Gemini 32 or similar with shoal draft. What about the Slider with a 10/15 hp outboard?

[Wavewacker]

Wow, would be very nice in aluminum! My garage is not that big. Someone put a hydrofoil between the pontoons of a pontoon boat with a V8 I/O, performs like a deck boat (almost....got to watch what I say here, lol)

Wonder what the draft is, I was thinking the OP would need a much smaller cat, like a Gemini 32 or similar with shoal draft.

[specmar]

Draft, with 44 passengers, is 25".

[Deering]

Hmmm, tough to see the mast in those pics, specmar, given that iuli was seeking a sailing boat...

[iuliradu]

Originally Posted by Deering

Depends on many factors. What's the depth of the river? If it's shallow, then you'll want a cat design with retractable dagger boards rather than fixed keels and rudders.

Sailing cats are generally quite beamy. Rivers are often narrow and crowded. Running a cat up the river to moor it is one thing. To use it to regularly navigate around the river's another.

Average depth for Danube is about 8 meteres, minimal depth I use for landing is about 2 meters. My concern is not about depth of the rivers, as it is enough for such a boat and also I will navigate only on main arteries.

My biggest problem is finding a suitable cat plan for regular river navigation and especially in cut-water. I will initiate 200 miles trips where I'll need to be able to navigate using only the engines. That's way I need a light design, able to be powered by twin 20hp engines, and in the same time large enough to host at least 4 persons.

Originally Posted by troy2000

I was completely unaware that the Danube Delta existed, until you started this thread. I've been reading up on it, and the subject is fascinating.

Are you really sure you want a catamaran? Although one would be quite practical in the ocean and the Danube itself, it seems to me that narrow, shallow and twisting delta waterways would be better served by a shallow-draft monohull with a retracting centerboard or leeboards -- particularly if you want to get off the beaten track, instead of just following the main traffic arteries.

Danube Delta is a wonderfull place, it has some unique kinds of vegetation and breadhtaking landscapes. If you would like to visit it I'll provide you valuable informations.

As I said, I'll navigate only on the main arteries, so as regarding river width and depth, dimensions of the cat doesn't represent any concern. I'm trying to find some plans suitable for engine navigation and in the time safe enough and stable for costal sailing trips.

I'm sure I want a catamaran, it could be proven beeing faster that a monohull, lighter and roomy. Another important reason I choose building a cat it's about it's charm, I'm sure that I want a cat, rather than a monohull !

In conclusion, if anybody of you can guide me in finding ( to buy ) some plans for a catamaran suitable for long engine cruises, like 300 miles along the river using twin small engines (like 20 hp), spacious enough for at least 4 peoples, stable and safe enough for short sea cruises I'll be fully grateful !

I'll also be very perceptive if you prove me that it's very difficult to find such a design and it's better to find some plans suitable for sailing or only for river cruising.

[iuliradu]

Originally Posted by specmar

The boat is 14 meters x 4.5 meters and is designed to be cut automatically by computer controlled machines. Pre cut-parts can be provided from the Netherlands. This is a very efficient method of construction, reducing man hours to construct the hull by a considerable margin. Boat is fitted with a hydro-foil between the hulls to greatly reduce fuel consumption. Designed to comply with ocean sea conditions.
We presently have a number of our mono hull designs under construction and operating on the Black Sea as high speed police boats.

Thank you for resources you have posted. Actually I'm interested to build a wood catamaran because of costs and facility. Even it looks great I'm sure that pre-cuted parts are quite expensive, comparing to wood.

[Angélique]

Hi Iulian,

There are just a bit too many to name just one. Notwithstanding here a few from the list to look at - Mike Waller - Richard Woods - Bernd Kohler - but you can look at many more, see the first link.

Good luck!
Angel