is length or hull shape more important for handling rough waters?

[oceanfrank]

I have a really stupid question and it's highly theoretical so hopefully nobody jumps on my about being unsafe 'cause i'm not about to put any of your theories into practice do not worry.

I am a long ways away from buying a boat but i am wondering what to look for. when it comes to big water like bays or near shore ocean for fishing and whatever i see people say to look for length but i also see people say to look for a deep vee hull.

I am not understanding the interplay between length and the hull shape. I know the the best boat for bigger water is a long boat with high freeboard and a true deep vee hull. but if you had to, had to pick one, is length or hull bottom shape more important? i.e. say you have a 14' little gregor or something with a true deep vee, or you have a 24' like one of those hulls that maybe has the pointed bow but is mostly a flat bottom (can't think of a good example), which is preferable for, say, 3ft waves?

again i just want to reiterate that I'm not about to take either out in gigantic waves but taking these extreme examples helps me work through the relationship mentally. thank you

 

[SeaDooSam]

I would go for a deeper v hull over length. A flat bottom will rattle And bang you and your engine to pieces

 

[ondarvr]

The deep V allows it to work better in rough water no matter what the size, but increased length helps improve any design in rough water, so they go hand in hand.

 

[Ned L]

The experience of the operator is far more important than either.

A deep V will allow you to move faster more comfortably,.... up to a point. If it gets really sloppy, to the point that you really have to slow down a deep V will roll a lot more.

 

[jimbo_jwc]

I like the variable deadrise hulls , and the old seacraft boats 20-22 ft on the great lakes as they still easily trailer when you want to move to another launch ,port . This is Scotto Australian copy..

 

[southkogs]

I am not understanding the interplay between length and the hull shape.

I think you want to be a little careful and make sure you realize that size can overcome some things regardless of hull style, and hull style can overcome others regardless of size.

A box that is 1000' long and 60' wide will handle the big ocean water better than a boat that is 50' long with a deep v hull. In that case - size wins. However, take a 1000' long boat with a deep v bow with lots of rake, and it will out perform the box. In both of those cases you're more of displacement hulls too.

The flatter the water, the more you can plane on top of it. The rougher it is, the more you need to stay in it and displace it out of your way. The bigger the waves, the better a larger boat will handle the rough water.

Welcome aboard.

 

[Old Ironmaker]

I'll take the shorter deep V any day than the flatter long boat. I boat on Erie 99% of the time. I imagine the water where one boats is a factor as well as weight. Shallow big lake with big seas (Erie) vs. shallow sandy rivers or bays where sandbars suddenly appear over night. The shorter deeper ocean going freighters will handle seas that would snap a long shallow Great Lakes Ore boat in half.

 

[tpenfield]

One thing that goes along with the 'deep V' is the beam (width) of the boat. Your deeper V boats will tend to be more narrow (less beam).

I went from a 24 foot 24 degree V boat to a 33 foot 20 degree V boat. The 24 degree hull handled certain aspects of the chop better, but the 33 footer is less airborne as it can transition between the waves better.

Degree of V, width of beam, and hull length all play a part in rough water handling. So, if it is your priority, get the deepest V (usually 24 degrees), narrowest beam, and longest hull that you can within your budget and other constraints.

 

[JoLin]

Southkogs and tpenfield summed it up very well. My question, first and foremost is, how and where do you intend to use the boat? My 1999, 24' Chris Craft express was the best rough water boat I've ever been on under 30', but it sucked for weekending. The hull design resulted in too many compromises in other areas of the boat. My Carver is damned near perfect for living aboard for up to a week, but it has a shallow V hull and is a lousy rough water boat. I've never felt unsafe, but it gets pretty uncomfortable at times. Since it fits my needs perfectly about 90% of the time, I just slow down and tough it out for the other 10%.

My .02

 

[shaw520]

While doing research in my ever going quest for a Trawler Ive learned a couple things. For pure ocean-crossing capability, a full displacement hull is key. These boats, which are often ballasted to increase their range of stability to 90 degrees or more. A displacement hull?s round bilges, upswept buttocks and emerged transom create very little form, or wave-making drag at these low speeds. All those molecules of water being displaced by the hull separate and then regather gently and gradually, making smoother transitions in the water. But due to their relatively slower speeds, its unlikely you'd be interested in a full displacement hull.

 

[harleyman1975]

I like a bigger boat in rough water as I would be going slower...in a chop give me a deep v every time!

 

[dingbat]

It really depends on what you want from a boat.

The old adage that there is no replacement for displacement says it all. The Chesapeake Bay Built is one of the most stable boats I've ever run.

The deadrise at the transom is one of the most misunderstood attributes of a boat. I'll take a variable deadrise hull over a "pure" deep vee in a heart beat for stability reasons.

 

[oceanfrank]

I like a bigger boat in rough water as I would be going slower...in a chop give me a deep v every time!

hey so what is the difference between rough water and chop? i've been using those words the same.


dingbat : "The deadrise at the transom is one of the most misunderstood attributes of a boat. I'll take a variable deadrise hull over a "pure" deep vee in a heart beat for stability reasons."


that sounds like a really smart thing to say, but maybe you didn't realize you were talking to such a dummy. can i ask you to explain a little more? thank you

 

[tpenfield]

Grady-White "Sea V2" is an example of a variable deadrise hull. The angle of V of the hull is more variable than traditional V hulls, giving a sharper V at the bow and mid-section of the boat, while having less V at the stern.

 

[ondarvr]

There are no right or wrong hull shapes, just some shapes that perform better when used in certain ways, all are a compromise, you just try to pick a design that works for how you use the boat most of the time.

 

[harleyman1975]

My thoughts of a "chop" is under 1 ft waves. Rough water is bigger than 2ft waves. but you are going to hit a point where the boat cannot perform on plane and you will have to slow to displacement speeds.

 

[Doh]

There are no right or wrong hull shapes, just some shapes that perform better when used in certain ways, all are a compromise, you just try to pick a design that works for how you use the boat most of the time.

Exactly, the right answer. There is also water conditions, fore/aft or side winds.

The lake I usually run in is Fresh Water, where 10-15 mph prevailing winds cause 1-2' Chop that usually quarter Starboard upstream. Deep Vee does smooth out the ride and rocking. When the 20-25 mph 3-4' rollers(they come in 3's) Head/tail winds come, length helps more than Vee. 18+' rides 2 waves, under 18' the bow tends to ride down into the on coming wave. 25-35 mph head/tail, you need 20' to ride the wave spacing. I have "Stuffed the Bow" on more than one occasion, with 17.5' Deep Vee. one time a foot deep into the on coming wave. Quartering those winds, you tend to ride in the trough more than bouncing through them.

 

[ahicks]

There are no right or wrong hull shapes, just some shapes that perform better when used in certain ways, all are a compromise, you just try to pick a design that works for how you use the boat most of the time.

Yes, have to agree. The OP's question cannot be answered with any degree of accuracy without more data being attached. The length of the boat is generally determined by one's budget, and whether it's going to be trailered or moored most of the time. Hull design is generally a function of how fast do you want to go, and how rough that water will be.

Already mentioned is the fact "rough" water is going to mean a lot of different conditions. Somebody said over 1' is rough. I would welcome him to an area on bigger water, where he can see guys having a blast in 4' conditions, who think nothing of that.

Before you pick a boat, or while picking one, you have to very carefully determine your new boats mission, and your budget, THEN you can start assembling useful data that you can use to make decisions.

One note I can share is that true deep vee boats can be a pain when trying to cruise at displacement speeds. They wander like crazy, requiring constant steering input to maintain direction....

 

[jbcurt00]

DOH, please take note of how long a topic has been inactive. After 90days w no new posts, treat them like library books: for research only, and not to be written to.

Thanks
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