Cackler adjustments

on a boat the size that we are talking about.....still they wouuld be the "pure Cat ass", if you ask me, if someone put them on one. Anyone that has ever ridden in a flats skiff, (also small but much faster), and seen what the electric tabs can do as different water conditions are encountered, would want them on their boat if they would fit, and if they could afford them.....

On the Devlin boats I think the Smart Tabs would be perfect, (except of course for those times when someone launches down the side of a dike or some other "well, they won't work for me because ONE TIME, in the life of the boat, I had an application where they would have been a problem---to which I would respond--name ANYTHING that is PERFECT everytime), and would provide "enhanced" performance over those silly ass little wooden door stops.....

I've been trying how to respond to the Sage Grouse question without pissing Dave off when I dispute what he had to say about their "eating qualities".....I'll post "my thoughts" to that bird on that thread....

Steve, GET THE LEAD OUT, Sutton
 
Steve,

I'll concede the point that trim tabs would be a fine to good (maybe very good) solution for me. I have been planning on making a set of manual ones and trying them. The main reason is that wedges can't account for the variability in loads I carry and that tabs would allow the flexibility to match the conditions.

For me, however, the smart tabs would be aweful. I continuously hunt the boat so tight that I have to pull up the motor and walk the boat out of the shallows. I've looked at the smart tabs and they drop way down. I hunt in weeds quite frequently too. Additionally, I woudl like tabs that are a little tougher than the stamped aluminum smart tabs, so I can use them as a step. Fianally, I can't help but think they would really hamper backing, which I spend a lot of time doing.

T
 
I'm confused?? Are these (cackler/snow goose) good boats or not? The wife and I have been looking at 16" lunds but would also consider building one of these two boats instead.

Do any of you guys fish out of these boats? What are your impressions? I want a two man hunting vessel and a 3 man fishing boat.
 
First Hitch says that he no longer believes that DUBYAH will replace God when he retires from the Presidency and now you admit that tabs are a good idea.....

I'll concede that the Smart Tabs may not be the answer to your particualr application and that you may benefit from something "tougher" that can be used as a step, etc......

Geez alou I feel a BIG sale coming on as clearly ALL of the stars in the Universe are obviously aligned....

Steve
 
I'm confused?? Are these (cackler/snow goose) good boats or not? The wife and I have been looking at 16" lunds but would also consider building one of these two boats instead.

Do any of you guys fish out of these boats? What are your impressions? I want a two man hunting vessel and a 3 man fishing boat.
Click to expand...


There is little to be confused about, as far as seaworthyness and huntability there is no comparison between a snowgoose (decked, wide and low profile) and a 16' aluminum boat. In ugly weather, I would take a 16' snowgoose over an 18' Lund Alaskan. In hunting situations where hidibility is important, the profile of a snowgoose is about 6-12" lower than the top of the outboard. Given its beam a snowgoose can transport a lot of weight safely.

I fish out of my snowgoose on Long Island Sound all the time. It isn't a very good fishing boat for me, relatively speaking, but this is the ocean and most people here fish 20'+ boats. If you were primarily perch jerking or something like that you could fish 3, but you have a cockpit that crouds your space. 3 can't cast and probably only one, unless you have someone standing on the deck. It is a wet boat as well, but that shouldn't be surprising given its low freeboard. I say it isn't a very good fishing boat, but I've brought a lot of fish back to the dock in it.
 
I don't understand what all the fuss on porpoising is all about. My BB2 almost tossed me out when I first dropped the hammer on it..tried to see if MORE speed would stop the bucking and settle down. I guess I looked like one of those off shore racers when I went by..jumping out of the water..hitting the water..jumping out.... I cured mine by raising the motor up. I raised it because water was shooting up in front of the motor and coming in in gallons over the transom. When I got to the point of no water boiling over, the porpoising mysteriously stopped. I'd recomend that all builders leave the transom at LEAST 2 1/2" taller than the "recomended" shaft length of the motor and work it down from there if need be. Pay attention to the angle of the total transom too..not just the motor well part.
 
I take my boat up to a fresh water lake in VT and there's a friend who fly fishes from the front deck (I don't fish, I'm not patient or smart enough). It's a relatively flat deck with a slight camber to shed water. He likes fishing from it.

Wedges are simply permanent smart tabs except they don't bust off when moving the boat off of a rocky sand bottom when the tide starts going out. Like Tod, I drag my boat into some incredibly shallow environments. I used 5 oz e-glass and a layer of 6 oz "normal weave" fiber glass. I've scraped a lot of rocks, but haven't dinged the hull yet. The middle keel has taken a beating at its lowest point. The boat has seen a lot of ice as well.

I clocked the boat at 30 with me and my son and a full tank of gas the other day when we went out to see the Tall Ships. The boat was built heavy - too heavy, but it doesn't creak or moan. It's solid which is good because our bay here in RI is never flat.

And finally, regarding the raging wedge debate here on the Duckboats.net forum, it'll never die as these boats that we all love will never die.
 
Having built BBIII, Honker and now starting Cackler I'd like to offer my thoughts on what I believe to be a few misconceptions.

If we believe that the term 'rocker' refers to a modest upward sweep in the aft section of the hull, a review of the the plans for each of the above will show that there is no difference in the lofting dimensions from midship to stern. Therefore, none has ANY aft rocker. The same applies to Snow Goose. Unlike BBII, these are all pure planing hulls.

Why do most (all?) have a propensity to porpoise? I suspect the majority of our configurations have battery and gas located in the aft storage compartments. Many are using comparatively heavier 4 stroke engines. All this combined with our own weight (and I have yet to hear of any of us complaining about being underweight) places the vast majority of the load well astern in the cockpit. This presents a TRIM problem and NOT a flawed design. A more comprehensive description can be found here (try not to get caught up in the 'sales pitch' anxiety):
http://boards.trailerboats.com/cgi-bin/trailerboats/ubb/ultimatebb.cgi?ubb=get_topic;f=6;t=000659
As you can see, the issue goes well beyond duckboats.

We normally don't know if our newly constructed 'pride and joy' will porpoise until first sea trials and we then start looking for solutions. We add on wedges, install Doelfins, Smart Tabs, etc. until we get the performance we thought we should have had from the beginning.

I've installed "Step-N-Trim" tabs on Honker as they allow for manual adjustment for 'average' load conditions as I switch between hunting and fishing. As importantly, they serve as a solid step in the (hopefully) remote event that I need to reboard. My hunting conditions range from tidewater and marsh grass on the Lower Columbia to rocky shoreline on the Upper Columbia. In over 50 days of river hunting last season I've yet to experience any downside to the tabs.

Brad Taylor, you can rest assured that these are all good boats and, with the choices available, I'm sure you will find a design that suits your needs.
 
Pete,

I completely disagree with your assessment. Anyone interested take a look at Devlin's drawing of the snowgoose.

http://www.devlinboat.com/dcsnowgoose.htm

The hull is rockered along it length at waterline and performs as a displacement hull at low speeds (as all boats do). The rocker causes bow lift as designed. You talk of the rear portion of the hull being flat and that it is a planing hull at speed, this is relatively true. BECAUSE OF THE PRONOUNCED ROCKER in the length of the hull (that gives it the desirible performance characteristics when not planing) this planing portion is short and the hulls are prone to porpoise.

Design flaw, no. Compromise, for sure. My issue is that Devlin does not include a discussion in his plans pr book and takes the stance, build it and when it doesn't work call and figure it out. I talked to Sam before I built, he said build it to spec and launch, which implies to me that there is a chance that it woudl perform normally. I knew it would not plane without propoising. From what I understand, no snowgoose that has come out of his shop has performed without wedges. I have an issue with that attitude.

T
 
OK, I'm in process of building a model of Cackler. I pulled out the plans for Snow Goose and my model of Honker. Here's Snow Goose with a scale laid along the aft section parallel to the aft portion of the keel. I can't identify any curvature which leads me to conclude that it has no rocker:
snow.jpg
Similar pic of the scale on the Honker. If there is any rocker I sure don't see it.
honker.jpg
Cackler looks the same. to me.
cackler.jpg
I'm wide open to discuss and welcome any/all diverse opinions.
 
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of the hull not just by laying a straight edge on the "flat" of the hull....

Move that staight edge up so that it is "balanced" on the centerpoint, (pivot point), of the hull and I'm betting you start to see the "rocker" that is in those hulls.....Certainly not the amount that is in my Barnegat which is less than is in Perry's Barnegat which is more than the Mallard but I'm with Tod as to it being there.....

Course I've neverr built a boat before but I have read a few defintions of "rocker" as it applies to boats.....

Show me a picture of the tabs on your boat.....

Thanks,

Steve, GET THE LEAD OUT, Sutton
 
Steve, my understanding of rocker is the curvature of the hull whether at the bow or stern. Again, I'm open for further education.

If we position the straight edge at midship we will find an upward direction toward the stern although it would be a straight line and not a radius.

My point remains that porpoising is considerably less a product of hull shape on the boats under discussion that it is of trim. You may recall my failed experiment with the 115 (467 lbs) which created the most severe porpoising I've ever experienced. Of course the effect was exacerbated by the 110 lb kicker. I didn't find out until later reading Tolman who states anything over 300 lbs on his 18-20' boat will result in trim problems.

Here's a link for some additional info:
http://boards.trailerboats.com/cgi-bin/trailerboats/ubb/ultimatebb.cgi?ubb=get_topic;f=6;t=000659

Also, Google "What causes boat porpoising?" for some additional scoop.

Here's the pic of my transom:
IMGP0414_1.jpg
 
Doesn't have to be "much" it just has to be there. That said I'm certainly in no position to disagree with you that the "rocker" is "minimal" or that "trim" is a greater factor in porposing than is the rocker......

As I said I've never built one, or for that matter, even ridden in one of the models that we are talking about....that doesn't seem to negate the simple definition of "rocker" though.....

Love those tabs...sounds like exactly what Tod was looking for, something strong enough to use as a step and that will withstand the rigors of shallow water choked with weeds.....

Thanks for the picture...

Steve
 
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Pete,

Yes, no or little rocker in the planing section of the hull.

Porpoising is defined as instability at speed, resulting in the bow giong up and down as the center of balance moves. The hull raises to a point from lift, the center of gravity moves forward (because more hull is out of the water when the bow lifts) when the pull of gravity exceeds the lift the hull falls. Repetition of this cycle is porpoising. But, of course, you know this. Lots of stuff contributes to porpoising (as lee said motor too low does, , overpowering, if the rear of the hull is rounded too much, rocker and load). I agree with your points, loading is important, overpowering, etc... but length of planing surface also contributes.

Look at those hulls you posted above, especially the snowgoose. The flat portion is small relative to the length of the boat (planing surface less than half length of hull). Look at a boat yard at modern planing hulls, the flat portion is 3/4 or more of the hull length. Look at a jon boat or small aluminum of any sort. On my snowgoose half or less of the hull is in the water, look at my avatar.

Here is a question that I'd like the answer to. If porpoising is the result of instability at speed, wouldn't a boat with a short planing surface be more instable?

Hey where did you get those tabs?!?

T
 
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Sorry guys but I have some sad news. I've learned that the company that made the tabs was bought out and they are no longer in production. I'll do my best to find out more and see if the new outfit has any plans to manufacture.
 
Hi Pete,
Very thoughtful post. I am just waiting for my epoxy and glass before I start building my Cackler. As I am analyzing the easiest way to lengthen to boat, I thought of adding 1" between stations, 14" total, and 2" to the beam offsets. I noticed that stations 6-14 were all the same dimension which means a straight keel from station six aft.

As this discussion progressed I wondered how Boston Whalers and other planing hulls were shaped, like Todd says, what percentage of their bottoms were flat versus the lift of the forward sections. I think small heavy duty trim tabs like you show in your picture may be the most practical solution if you don't want "door stop" wedges glued to the bottom of your boat.

Regarding my earlier experience with our Snow Goose where I hadn't noticed a porpoising problem, I think Dave Clark is right about running the boat loaded. We finished our boat just in time for duck season and bypassed sea trials, we just loaded it up and went duck hunting. That may seem fool hardy but we had less than a mile to this hunting spot and figured we could putt-putt the boat there if need be. We put a large fuel tank under the forward deck, a center console and loaded the boat with lots of gear, so without intent we are balanced pretty far forward. As Todd and I were discussing earlier, the boat may porpoise like hell empty running wide open, that hasn't been a problem for us in three years as we never run with an empty boat.
 
I became aquainted with "rocker" back when I did a lot of canoe-ing. Whitewater boats have a lot of "rocker" so you can turn sharply around obstacles..it makes for a poor touring canoe since it takes a lot of strokes to keep it going straight..very inneficient for that purpose. Take the line from where the bow becomes the bottom of the front end, to the bottom of the transom..then you will see what "rocker" the boat has. Porpoising is the boat trying to get out of it's own bow wake and like Tod said, it does it, then can't support itself and comes back down to do it again. I also believe "rocker" is measured from the centerline. My BB2 has quite a bit of rocker and I find it handy when pulling it through very shallow water..I can push down on the bow to lift the stern..or have Colby stand on the bow which gave me a lot less draft. Like someone said, these are duckboats dammit..everyone expects them to go like the boats that pull skiers at Cypress Gardens. I am probably the worst one here when it comes to trying to get my boats faster but I am a speed freek and enjoy the challenge.
 
Pete,

The Cackler & Honker hulls are similar. The Tolman's hull is very similar to the Cackler and Honker. The Snow Goose and Scaup hulls are similar.

When I was building the boat, I once put the boat hull on the ground and the boat would pivot like a top around the protruding "rocker". It was balanced almost perfectly. I could pick it up and move the boat around on its pivot point.

Trust you are well, best, Andrew
 
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