My thoughts on how to drive yourself crazy choosing a hull design!

Take you for a day cruise.. being afloat helps the pain..
Why you don't write up the SOR's ie the requirement's you wan't to gain..
-number of passangers
-range
-speed
-comissions
etc... just be reasonable with your wishes

 

Right so .... as an example,

I took a few trips on boats and decided to go for the following:
1- Range: Close to shore operation, 1 KM from shore max
2- Passengers, about 4 mostly for fishing but may need as around 7-8 for recreational cruising and underwater photography.
3- Red sea water, rather high salt concentration not fresh water
4- Although its sea, its basically the Suez canal so water is not open and offers some protection from high seas. The frequent passage of huge freighters and ships does send some rather nasty waves. So good stability and ease of moving and standings is a must (also for standing and pulling fish in etc...).
5- Speed is not a major factor as most time is spent fishing so a decent performing economical engine is more important than a high speed one.
6- Lack of yards in the area means reliability and long lasting is important!! (else i have to move the boat around 350 + KM).
7- Roomy interior space for ease of moving inside the boat....

so ... does that qualify as reasonable wishes ?

 

Are those that unreasonable !!!

 

I have a question, is there a major difference in the bottom hull shape for river boats as appososed to sea variants?

The reason is i took a ride in 2 speed boats, both almost the same size but one was open bow the other was closed deck. The shape of the hull was different as well and boy there was a difference !! one seemed to struggle with rough waves while the other had more slicing feel to it.

Any thoughts? or is it just the different hull shape from different manufactures and thats it ?

 

Yes.. The difference with planing huls is (usually, so generalising now) the amount of deadrise of the V bottom. More V more seaworthines, lesser V is more stable and economic hull. With displacement huls the major difference is the lenght river boats being narrower. For you something semi planing could be the best..

 

Thx Teddy !!

Is there any examples on the differences? maybe a link with pics or something?

 

Look here.:
http://www.boat-ed.com/sc/course/p1-2_hulltype.htm

 

You might read some of these http://en.wikipedia.org/wiki/Hull_(watercraft) and
http://www.kastenmarine.com/articles.htm
do also a search in the forums with "hull shape" (titles only)..

 

Sweet ! thx folks !!

So the attached hull design is a planning hull but acts as a displaced hull at slow speed?

What are the common mistakes or bad design shapes that any one ran into?

Although i am going for the fiber / wood building, a friend wanted to buy a used fiber boat and thinking i am the expert he is taking my advice (lol the blind leading the blind if you ask me!!! I told him all ask the "experts" and get back to him!)

I will take some pics of the boat's hull he wants to buy and post it later on ...

 

Here is the boat my friend liked (well the hull part anyways)

 

What would be the experts opinion on this particular hull shape?

 

Quite ordinary medium deadrise V-bottom. Can't say if it straight or with rocker without a side view..

 

Thx Teddy, i attached a side picture.

The problem in Egypt is that a LOT of lake boats are bought and sold as sea boats making them fracking uncomfortable.

I lack the experience to differentiate between both im having to bother our experts (whom are stars i might add!)

 

That boat is adequate for short trips close to shore. Can't say anything more about it's seaworthiness. Deck, self bailing, freeboard, engine, weight, loadability etc???

 

Its built in Egypt so basically depending on requirements, ill see if has further information for a clearer picture.

Thx