posted 08-12-2006 12:27 PM ET (US)        

One of the attributes of the constant-deadrise v-hull is very good tracking in a following sea, and very little tendency to bow steer. By bow steer I refer to the tendency of a boat to have its course influenced more by the bow than by the stern and the rudder (or engine). Boats with a constant-deadrise v-hull do not tend to go veering off course if the bow digs in when running down the face of a big wave in a following sea. The boat will run down large waves without wild changes in direction.

The rise in popularity of v-hull boats lead to more experimentation, and soon there was the deep v-hull, where the deadrise angle was increased beyond 20°. As the v-hull deadrise was increased, the ability of the hull to slice into waves was improved. In situations where it is desired to run into large head seas, the deeper the v-hull the better. However, there was a price to pay for the deep-v: as the hull form became more acute, there was less lift available to get the hull onto plane, and more horsepower and speed was needed to achieve planing.

The logical evolution continued and soon the variable-deadrise v-hull was invented. The bow was made sharp and deep to cut through head seas, and the stern was tapered into a flatter v-hull to give more stability at rest and more lift for planing. This design often has a tendency to bow steer, particularly at low speeds. Operating a boat which has a strong tendency to bow steer can be very tedious, as the boat will not hold a course line, and the helm must be constantly corrected to keep the boat on course.

I now have almost ten seasons of experience with a classic Boston Whaler hull, and I have come to appreciate its characteristics. One of the most impressive is the hull's lateral stability at rest. When you board a classic Boston Whaler boat, the hull's lateral stability is evident the moment you put your weight on the gunwale: the boat hardly leans over in response. Running downwind in following seas or motoring at no-wake speeds, the hull tracks very well, and the boat does not veer off course. Constant attention to the helm is not required. Going into head seas is not the hull's finest hour, and, especially if the wave face is taken at about a 45° angle, there can be an awful hull slap. The Whaler hull really does not like a 45° approach. It is better to go head-on to a wave and let the bow try to slice it. But once you get into the longer hulls, the boat can usually float from wave crest to wave crest atop of the seas, and the ride is not bone-crushing.

Just recently I spent a week cruising on the Ottawa River and began to reflect on my boat's hull form and how it was working in this sort of application. In riverine boating you generally do not have large wind-driven waves to contend with. Watching the fuel tank level gauge drop as we were running on plane at 27-MPH, I started thinking about how a hull form with a bit more planing surface aft might be more fuel efficient.

posted 08-12-2006 07:20 PM ET (US)            

Weight of the boat, Expected user speed range, Compromises that are important to the owner, Maximum length wanted by the owner, Sea conditions that the boat will be used, Number of people or weight to be carried. Fuel usage. Overall looks of the boat. And I am sure much more.

For my area, I know that I did not buy the best rough sea boat, That would have been the locally made copy of the 22 foot Monza Hull. The Monza also has a constant deadrise. There is not a newer or variable deadrise boat in this area that is better. I just couldn't satisfy my Whaler Addiction with this boat.

posted 08-13-2006 02:24 AM ET (US)            

I do really like the variable [deadrise v-hull] however. It is versatile. I initailly did not like it, but after four to five years I got the other variables you mentioned dialed-in. In my opinion, it was impossible to get true benefit from the bow when needed because of relative buoyancy, light weight of the boat, and high planning speed.

My solutions:

Strict weight distribution for my gear and passengers. I have found that if all tackle and food goes up front and two guys at the helm, I can keep the bow in the water much better. If three guys go, then one sits on the cooler forward, if four guys then three at the helm area, nothing in the stern. This improved things a lot.

I felt that pounding four-foot waves at 18-MPH or better did not make for a comfortable ride even after managing weight. Airborne too often. I thought about trim tabs, but stern is not built for it, so for me the turbo lift and a painstaking evaluation of props solved my planning speed, plus other benefits.

Can plane as slow as 12-MPH and have more control over bow than I ever imagined. So in four-foot waves I can maintain a speed below flight levels and really knife through wave with little stern movement. Benefits still present at higher speeds, too.

Non-whaler friends who fish with me always remark how much better my [unrecognized acronym, possibly "OUTRAGE 17" intended] rides than their 22-foot something-or-other.

I believe the variable deadrise makes this possible, but on smaller boats getting some weight forward and lower planning speed is important.

posted 08-13-2006 11:43 PM ET (US)            

Then we get to the Whaler 13 footer, a strange hard riding little tri-hull boat with a hooked bottom.......

posted 08-13-2006 11:47 PM ET (US)            

It is hard to make a direct comparison between our boats as my hull is longer, and generally longer boats can stay on plane at lower speeds. In my case I can be on plane at about 12-MPH, although that mode is not very efficient as the stern is digging a big hole in the water and wave-making in the wake is quite large.

posted 08-14-2006 10:04 AM ET (US)            

There is clearly a trade off between deadrise, bow entry angle and overall handling. The classic Whaler hull design has made a trade off between head sea and following sea handling.

quote:

---

Going into head seas is not the hull's finest hour, and, especially if the wave face is taken at about a 45° angle, there can be an awful hull slap. The Whaler hull really does not like a 45° approach. It is better to go head-on to a wave and let the bow try to slice it.

---

posted 08-14-2006 07:17 PM ET (US)            

JIMH: Moppie was a 24 degree deadrise bow to stern.
Binkie: Moppie was Dick Bertram's wifes nickname.

variable deadrise hulls are not anything new, that is true, and they are perhaps nowhere more prolific than here on the Chesapeake Bay. In fact, for those of you who have never spent much time in MD or Va, the nickname for the big traditional wooden workboats of the Chesapeake is "deadrise". This phrase/nickname is derived from the extremely variable deadrise common in these hulls, which can range from upwards of sixty degrees in the bow to as little as 0 (flat) in the stern. The hull when viewed from below is a constantly changing curve as it sweeps aft.
But these boats, except when grossly overpowered, are not capable of achieving even the beginning stages of planing. They are displacement hulls, pure and simple, meant to cut through the waves and not to run over the top of them. (part of this is due to their size, averaging probably between 36 and 42 feet.)

A constant deadrise hull can slice the waves better than your average carolina skiff, but one drawback that is not noted here so far is that a hull like Moppie, while great at speed, will roll much more substantially at rest in heavy seas than perhaps my Montauk for example.

Variable deadrise hulls in the modern definition seem to be an attempt at a magic bullet, in effect an answer to the boater who wants wave cutting ability to soften the ride, combined with the ability to have extremely shallow draft and more stability.

posted 08-15-2006 02:46 PM ET (US)            

Time is money. Most small boaters have more of the latter. So, the ability to maintain more speed in a chop is given priority over other attributes.

So, if you want a low powered boat that is miserly with fuel, planes at low speeds, is sea worthy under a variety of conditions, and is easy to handle, then you simply look for an old design. Older designs tend to be longer, narrower, soft chined, sharp bowed, and flat aft. Modern designs are exactly the opposite. The performance difference between these two extremes can be shocking--for better and for worse.

If you want to examine some older designs, the downeast lobster hulls are classics. Check out the Eastern 18 and the Seaway 18.
I

posted 08-15-2006 11:52 PM ET (US)            

http://www.huntdesigns.com/about_deepv_qa.htm

posted 08-16-2006 12:32 PM ET (US)            

How much does the angle have to change before it is no longer constant? How subtle is a subtle change? When I sight along the hull of my classic Boston Whaler it appears to have a constant angle. Perhaps there is a slight variation of a some minor amount, too small to be seen by eye. Shall we bore deeper into the minute of this discussion? Or would someone like to return to the original question I posed:

posted 08-16-2006 08:06 PM ET (US)            

The “Tournament” bow rider, and “Center console” models have significantly less weight in the bow area. They have far less tendency to “bow steer”.

I find the Walk-around has substantial, perhaps too much, weight up front. The hulls are superior in head seas. They are very smooth over very steep chop. Yet, I have seen and felt a very pronounced “bow-steer” in following seas. Also in taking the waves and/or wakes broadside.
The Walk-around hull needs plenty of power, close to the hull’s maximum horsepower, and then can “steer” out of trouble, or correct the “bow steer” by trimming engine(s) out sufficiently.
There has been many discussions on other sites regarding this phenomenon in Grady Whites from 24 feet and higher.

A friend had a 1997 24’ Grady White Walk around with a 260hp Merc I/O.
This proved to be marginal power for that hull. The Walk-around model was so heavy in the bow, that in a medium quartering sea, or passing another boats wake, or god-forbid a following sea, THAT BOAT WAS DOWNRIGHT DANGEROUS. She did perform admirably in a head sea.
My friend had a love-hate relationship with that boat, and finally sold it last fall, due to “lack of confidence” in that hull.
He has steadfastly stated “that no boat does so many things well as my 25 Revenge WT.

He has since moved to a 2450 Walk-around Pursuit with twin 115 Yamaha 4-strokes.
This too is a variable dead rise hull, and a deeper V than the Grady. This too has some bow steer tendencies, but not as dramatic as the Grady, in part, due to the twin outboards which, when trimmed out, gets the bow out of trouble.

There is no “perfect” hull for all conditions. All are “trade-offs” in one respect or another.
It seems to me that where ever there’s a Doherty hull, they are highly respected. Boston Whaler, Edgewater, and now Everglades. They appear to do mostly everything pretty darn well.

posted 08-16-2006 10:40 PM ET (US)            

It never ceases to amaze me how two different maker's hulls which appear similar at first glance can ride totally different once you get them into some chop and wind. Where I fish, some of the local brands have taken on "slang" names to match their ride:
RedFin = Wetfin cause you get soaked riding one across the bay
Carolina Skiff = SlipNSlide because of the way they handle
Pathfinder = Barfinder (thanks to a certain local guide who runs one aground weekly trying to follow the purpose designed shallow water boats)It's a bay boat, not a flats boat dummy.
BlueWave = Black-N-Blue Wave. That's what you'll be in a chop.
El Pescador = El Pesky Wh0re because they'll swap ends in a hurry if you make a sharp turn without first dropping the jack plate. Tunnel hulls with a deep forefoot tend to to that.

posted 08-16-2006 11:39 PM ET (US)            

Just wanted to get back to you, maybe clarify some of my points that I did not make clear :), much earlier in the thread.

With regard to planning in my Outrage 17 with a variable vs. your 18 constant - in my opinion too the constant plans much better. I noted this becasue I felt sometimes planning speed was too much for conditions and countered the apparaent benefits of sharp entry, and I felt my 17 delivered a similar beating going into the waves as you described yours.

With regard to weight distribution, did not mean to state the obvious. What I have learned about my variable and light (2052 lbs boat/motor) in rough water running, is that I needed to really weight the bow (100+ lbs on the casting deck, plus any people positioning). This reduces the bow poping up with each wave to my liking and comfort at speed.

The other step I described was the turbo lift (Chuck Bennett from Whaler turned me on to this). The control this device has on trim is remarkable. Some squatting at 12mph, no appreciable at 13mph or better. Stability of bow at speed in the rough is equally impressive.

My tinkering has made this boat much much better in the rough, by getting the bow down and keeping it there - thus actually benefiting from the sharp entry. These efforts allow me to run nearly level (no idea what percent that is) into reasonably rough waves at good speed. I have never stuffed it, although I will back speed down and trim down if better than 5's or some 4's.

I was able to completely change the handling attributes with this variable hull, and tried to propose that degree of flexiblity may not be as feasible with a "constant" hull.

Thanks for the great discussion topic !

posted 08-17-2006 06:23 PM ET (US)            

I'm not sure when Bayliner evolved but I know they were around in the late 70's and early 80's. I was well warned to stay clear of all of them. Especially the ones with the white (Force) engines with the cowlings removed. Guaranteed to lose a few hours towing it somewhere. The young dad with the giant red question mark STAMPED on his forehead, and the rest of the family curled up under the dash. Oh and never take your eyes off of them while in tow. Amazing how they will suddenly start, then try closing in on you to retrieve their tow line.

posted 08-18-2006 12:06 AM ET (US)            

This term comes from C. Raymond Hunt Associates. They use it to describe the hull they just designed for Southport Boat Works. Their hull is claimed to be designed specifically for the weight of twin V6 four-stroke motors, or more than 1,100-lbs of motor on the transom, not the puny 900-lbs of twin V6 two-strokes.

The boats look like darn nice boats, and I imagine the price is right up there in the same strata as Grady-White and Whaler.

Now one very interesting comment from that article is a reference to the better fuel economy provided by this hull, and in particular its ability to maintain plane at lower speeds (low 20-MPH region) but still get good fuel mileage. They say:

"Most hulls have a narrow band of maximum economy, usually over 30 miles per hour."

This is somewhat true for my own boat. The fuel economy peaks at 27 to 30 MPH. If I am not running in that band, the mileage falls off noticeably.

Vector off to this article for more background:

http://www.southport-boatworks.com/hunt4.php

posted 08-18-2006 06:39 AM ET (US)            

They must have made the right decision, because I've been seeing lots of them around Falmouth, Buzzards Bay and Martha's Vineyard.

BTW, Edward's Boat Yard took on the Parker line and they are selling great. I have never seen so many Parker's, particularly the 23' with a cabin powered by single 225 or 250 Yamahas.

I assume Boston Whalers #1 dealer Nauset Marine is still doing very well. With todays fuel prices, I'm continually amazed at the number of new premium boats I'm seeing.
New Whalers, Grady's, Pursuits, Regulators, Southports, Intrepids, and the number of Hinkley's blows my mind!

Jimh, you're right. These Southports are a premium boat with a premium price. Like you said, they are built for big time 4-stroke power, and it shows when you see them running.

posted 08-18-2006 07:29 AM ET (US)            

I have ridden on the 21 degree Deep V's, and yes, they ride in rougher water more smoothly than the 14 degree or 16 degree deadrise models. This comes with a trade-off, as you might expect, which is that the 21 degree deadrise models use more fuel to push them, as well as noticeably more rocking on the drift. I can't imagine what the 24 degree deadrise Regulators or Contenders are like at drift in this regard, but given my propensity to not enjoy such heavy sea-motion, I would imagine those models are not for me.

posted 08-21-2006 01:41 PM ET (US)            

I am not sure how to respond to your post, as I tend to have mixed feelings about it. Bigger is always more comfortable when we're talking about travelling in heavy weather or big seas, I guess.... It depends on your hull type. But theres' a lot of baggage that comes along with a bigger boat.(more fuel, more engine, more worries, though you might not be worrying as much about getting capsized or something like that)
If we are talking hulls, I'll take a small seaworthy hull over a large bathtub any day, but all the boats you mentioned are whalers, so you are ok there.