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

ok i am developing an "unhealthy" obsession with hull shape and design. Honestly its starting to scare me i have this uncontrollable urge to be able to "read" the hull and understand how it will handle the boat.
I know its crazy but i cant help it, really !!

With so many variables so many designs, so many conditions ...... what on earth are poor saps like me supposed to do ???? (except go crazy)
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The boat posted above it being refurbished, i will get the info (and pics) when its done soonish i hope

 

Teddy got the right information there with planing/ displacenment hulls. I'd like to mention that some planing hulls at slow speeds (displacement speeds) are a bit "unstable" in the direction, on some, it takes a lot of steering to maintain the desired course at slower speeds...

I also once more or less got into a physical fight during a discussion of/ wheter the strakes ( steglist ) in the lower region of the V-shape of a hull, was needed to go all the way back to the transom...(my opinion was that they didn't do much harm, if they went all the way aft to the transom). There was a fundamentalist listening in on that coversation....

Ok, I admit, I probably was wrong, but I still dont believe that we're talking of major impacts here...

 

Since the max distance to travel before stopping for diving/ fishing, a pure displacement hull could be the option to go for?
It'll require a smaller engine installation too. (As in cheaper).

 

Most of the persons in this forum are already crazy........

What to do; buy a boat, try it, if pleased with it, keep it... If not, sell, buy another, repeat until pleased state is reached.

Boats are like motorcycles;
an unhappy person, is a person who's bought the wrong one...

 

Regarding the displacement/semi-displacement/planing hull choice - if you intend to perform scuba diving (underwater photography, as you have stated) from the boat, then this requirement is a dominant one, imho.
In that case I would go for a medium-deadrise planing hull, perhaps a RIB. Firstly because it will give you a more stable platform for scuba operations. Secondly because, although **** rarely happens during dives it still might happen - and in those moments you want to run towards a nearest port with a medical emergency department as fast as you can.
Cheers

 

"When we remember we are all mad, the mysteries disappear and life stands explained." – Mark Twain

 

So basically everything is mutually exclusive.

If i was to summarize things in a way i can grasp, would that following be correct?

Displacement hull: Used if speed is not a key factor but rather is more efficient at lower speeds. (Ease of movement with a smaller engine).
Not able to achieve high speeds as compared to V (planning hull)
Tends to role a bit but is more comfortable at slower speeds than V's.

So would a fully displacement hull be more comfortable than a V equivalent? I.E rolling, breaking waves, weight shifting etc...

 

Hello ?

 

Hello.... (echo)
Depends... (the answer) of various things.
There's not such thing as a perfect boat. Even when a boat mysteriously happens to be perfect for some specific task, something the sea throws on us disproves it..

ps. so it's better to look something that mostly pleases the user, and to which we can trust our very lives on...

 

I understand i never mean better or perfect, i am just trying to categorize the different characteristics in my head as not to choose a hull that doesn't suit my requirements.

The more variables i understand the less the unknown factor and the happier i am !!
Its very difficult to get boat trials so im having to relay more on knowledge and reading ..

 

We can only state some generalistations.. Any two boats looking more or less the same can still have a totally different natures at sea. The only way to get real gap of their behaviour is to take a tour with them..
To get a bit more depth into subject you need a book, and another.. I got those books more than 1m on shelf, the NA's much more so you get the picture. Read Ted Brewer, Dave Gerr, Larsson&Eliasson and of course lot of good threads around here in the forums. Go into Stability subforum first..
BR Teddy

 

Aye that i will do, the way i approach new projects is usually break them down into different parts then tackle a small part at a time.

My major limitation is my fundamental weakness in mathematics (why i could not be an engineer although i wanted too badly), and so far all the files, PDF, E-BOOKS are written that way making it very hard for me to understand.

So i am having to learn in a different way which is interaction, research reading and feedback from experts (its the way i learn even back in collage).

So if lets say (for example) boat characteristics are 10 Variables, what i would do is keep 9 constant then change 1 (while learning about it) and keep going.
That way at the end i would have generated an idea on the whole thing

 

Good argument:idea: :idea:

Thats a VERY good argument for a fast as possible boat....
(once got a speargun in my knee.... not my own...., also know of some cases of "divers bend", too. Time is sometimes the major factor).

 

I take that as an argument for me not beeing mad, as I'm often pretty confused...

Edit; but a rib, as proposed above, is very good for most uses, and for divers, it has a lower freeboard, makes reentry easier. Just keep the sharp things (confused divers) away from the rubber, (normally not a problem with leaks).

 

OK now im blaming u guys for getting me addicted to boats, handing in my resignation and applying for a job in boat building ...

Honestly its all your fault !!! AND i feel fracking great about lol .... best decision (i hope, if not we are all mad so i have my excuse )