Flat Bottom or Vee Hull

[cybersniper]

Had some bad news in regards to my current project on the weekend so im now at a stage where i could be building a new boat from scratch.

I had a discussion with my dad in regards to the possibility of Building another Cabin Cruiser Sea Babe from scratch.

My Dad said if thats what i really want he is happy to go ahead and do that, however he said that i should have a good think about what i want now that im starting again from scratch.

One of the things he mentioned to me was that boats with a Flat bottom (or almost flat) like the Sea Babe can have a tendancy to be quite rough on the water when planing (He mentioned the boat pounds the water)
Were a Vee hull rides a lot smoother when planing.

I really like the styling and the classic look of the Sea babe, but could be swayed to build another classic if it matches the look i was going for. (or at least comes close)

What i liked about the Sea Babe: Love the Classic Tumble Home and the Raised front deck.

What are there Pro's and Con's to each of these hull types?

Im hoping these answers might help me decide on what i want to build.

 

[scoutabout]

Re: Flat Bottom or Vee Hull

The prevailing wisdom I have always heard (and experienced ) is that flat bottom boats = sore bottom sailors when it comes to riding a good chop.

Wider, flatter hulls do have the advantage of needing less power to produce a given rate of knots because they pop up on top versus having to cut through the water like boat with more v or deadrise. Also, Vs tend to be heavier, which again will require more power. Wider, flatter hulls will provide a more stable platform to walk around on while at rest, and of course are generally better in skinny water.

Just some random thoughts - your intended application, budget, and time you want to invest in construction will also play a part in your choice. I do like that tumblehome look too!

Good luck and let us know what you choose.

 

[mrdancer]

Re: Flat Bottom or Vee Hull

It's not too difficult if you use common sense and think things through.

Short, wide hulls with little to no deadrise plane easily and require little power once on plane. They are very stable, but can also beat you to death in a chop, depending on the boat's weight.

Long, narrow hulls with little to no deadrise won't plane quite as easily but are more efficient at slow (displacement) speeds. They also ride better in a chop (length spans wave crests, narrow hull has less width to pound against waves).

No deadrise = stable platform in calm seas as well as shallow draft; however, if you do become grounded, they are more difficult to get un-stuck. Planes easily, but handling at speed can also be tricky with a flat-bottom.

Large amount of deadrise = stable platform in rougher seas, deeper draft, unstable at rest, soft ride in the chop, requires much more power to plane.

Small amount of deadrise = average stability in most conditions, somewhat deeper draft than flat-bottom, but easy to get un-stuck if you become grounded, decent ride/handling in a chop, probably best option for most inland boaters. I'd shoot for around a six- to twelve-degree deadrise, depending on your shallow-water needs and rough water needs.

 

[Home Cookin']

Re: Flat Bottom or Vee Hull

A couple of misconceptions about the topic:

A deep V boat and a flat bottom boat do ride differently--but the difference is unnoticeable in a 14' tinnie or a 26' work boat.

When you read "deadrise" it typically refers to the angles at the hull at the transom. But what goes on from the water line at the bow, and on back, is more important. There are boats with a deep V or even a drop V in the bow and almost no deadrise in the stern.

Unless you have a significant length difference, it doesn't matter.

Anyway, from the way the first post is written, it is clear you need to do a whole lot more research--best by talking directly to boat builders. Generalities that you will get here won't do any good for a major choice like you want to make.

 

[cybersniper]

Re: Flat Bottom or Vee Hull

Thanks for your input guys.

Scoutabout in regards to my intended application for the boat, im just looking to have a bit of fun on the boat, whether that be fishing or just cruising around with my wife and friends. As for the budget im a very lucky boy because my dad wants to pay for the boat (well the main parts of it anyway...any luxuries is at my own cost)

Our family has always had boats in it so its only natural my dad wants to get me into it and im happy to accept and learn in the process.

So after much searching my dad and I have settled on a design we are both happy to build.
We have decided on a Bateau Open Classic 17

 

[Home Cookin']

Re: Flat Bottom or Vee Hull

cool boat!

 

[blackhawk180]

Re: Flat Bottom or Vee Hull

I helped my dad build one like that in the early 60's. We cruised around in that for years with an old Johnson 35 hp motor that was fast enough for me to learn to waterski behind. Great boat. I'll try to dig out some old pics and digitize and post them for you.

 

[southkogs]

Re: Flat Bottom or Vee Hull

...So after much searching my dad and I have settled on a design we are both happy to build.
We have decided on a Bateau Open Classic 17

Very nice. Looking forward to seeing it floatin'.

 

[crabby captain john]

Re: Flat Bottom or Vee Hull

Would be a great winter project....

 

[cybersniper]

Re: Flat Bottom or Vee Hull

Blackhawk180 that would be great to see, thank you very much. I do have some pictures of it from other members on the bateau forums but any extra pictures would be great to give me more ideas for my boat.

It definitely is a cool looking boat and im looking forward to building it with my dad as a project

I wont go into too much detail about what ive got planned for it in this thread because that's going a bit off the original topic.

Ill start a new thread for the new build and share my ideas there. Work on the boat probably wont commence for at least a couple of weeks as we now need to gather more materials and obviously wait to receive the plans.

 

[blackhawk180]

Re: Flat Bottom or Vee Hull

Looking forward to the build thread, cyber. It'll bring back very fond memories working with my dad. We used very few power tools back then and I still remember him sharpening the blades for the various wood planes and the wonderful curls of wood they would produce. (my job to clean up after him). Darn near built a wood drift boat a couple winters ago but decided aluminum was the way to go. First time I hit a rock, I was glad I did.