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When I looked at the stern shot of the unrigged boat, I could not help but wonder why there was no delta pad on the bottom of the hull. It would fit very nicely between the pickups and add to the efficiency of the hull - without hurting the ride. More speed, better fuel numbers and an easy place to put a transducer pocket parallel to the water surface are all good things. Have you done delta pads before on any of your hulls?
If anyone is wondering what a transducer pocket is, some builders make or mold a pocket in the bottom of the hull that is larger than most transducers. The builder also has a mold the same shape as the transducer pocket. The transducer that is going to be installed is dropped into the mold and is cast into a block of resin so it matches the pocket in the hull. The 'ducer is then attached with the usual through hull hardware, but is dead flush with the bottom of the hull, rather than sticking down. If you change electronics, pop the block out and mold the new 'ducer into a new block. Making a pocket in aluminum is easy. Weld it up close to size, finish machine the interior on a CNC and weld the pocket to the hull.
Jay, you better order a 3rd package , it looks like KernO wants one with a Box thingy on the bottom.
And this is the REALLY COOL thing about ALLOY ........What do you want on the boat and where do you want it ! There are no speical molds or magic , just ask the builder to build it .
You should see what the boys Down under come up with for ad ons ,some can be seen over on , www.aluminumalloyboats.com , there are also some build pictures and Video of the RockSalt34 there .
__________________ F350 4x4/ Dodge 2500HD 5.9L Cummins
Leaving the Picture of the Ford cuz I miss it
Pacific 2325 cc
Honda bf225
aluminumalloyboats.com
But I have a question (and if I'm right, a "point")...
On the bow flare discussion, I will say that having owned boats with/without flare, flare definitely helps in keeping you dry in a quartering sea. I used to own a 22' Chris-Craft WA with a lot of bow flare and she was extremely dry for her size. 'Course, with 15-20 knot winds on the quarter you're gonna get wet no matter what you're in.
Now I'm no naval architect, but it's my understanding that a lot of flare also provides additional buoyancy at the bow. Like when you're trolling a spread into 5' seas, or at anchor- the extra bouyancy keeps the bow from stuffing and the green water outta the boat.
When I looked at the stern shot of the unrigged boat, I could not help but wonder why there was no delta pad on the bottom of the hull. It would fit very nicely between the pickups and add to the efficiency of the hull - without hurting the ride. More speed, better fuel numbers and an easy place to put a transducer pocket parallel to the water surface are all good things. Have you done delta pads before on any of your hulls?
If anyone is wondering what a transducer pocket is, some builders make or mold a pocket in the bottom of the hull that is larger than most transducers. The builder also has a mold the same shape as the transducer pocket. The transducer that is going to be installed is dropped into the mold and is cast into a block of resin so it matches the pocket in the hull. The 'ducer is then attached with the usual through hull hardware, but is dead flush with the bottom of the hull, rather than sticking down. If you change electronics, pop the block out and mold the new 'ducer into a new block. Making a pocket in aluminum is easy. Weld it up close to size, finish machine the interior on a CNC and weld the pocket to the hull.
Kerno,
Great question.
The simple answer is ignorance and caution. The bottom (as designed and built) is a completely known and predictable bottom. No surprises. Having not done a "Delta" pad I just wasn't willing to do any experimentation with a new product. Stay tuned....
I went back and forth about 20 times but ended up with the bottom shown.
As an aside - I spent Friday afternoon with a gentleman named Dick Akers from Small Craft Engineering in Portland, ME. ( www.smallcraftengineering.com ). Guy has a brain the size Wisconsin and about 100 post graduate degrees. Bright guy. Although we weren't discussing Delta Pads we had a brief conversation about stepped hulls that opened my eyes to some of the hazards to untested, non-traditional bottoms. (He had served as an expert witness at the trial...)
As fr as traducer pockets are concerned we have just installed a 1kW "tilted element" transducer on one of our boats. Thing worked extremely well on trials and may negate the need for a "pocket". Pic:
Icicles at no extra charge!
__________________ Jay Perrotta, President
Rock Salt Alloy Boats, LLC
PH: 207-400-7404 jay@rocksaltboats.com
tobnpr - 1/12/2009 2:18 PM
On the bow flare discussion, I will say that having owned boats with/without flare, flare definitely helps in keeping you dry in a quartering sea. I used to own a 22' Chris-Craft WA with a lot of bow flare and she was extremely dry for her size. 'Course, with 15-20 knot winds on the quarter you're gonna get wet no matter what you're in.
Now I'm no naval architect, but it's my understanding that a lot of flare also provides additional buoyancy at the bow. Like when you're trolling a spread into 5' seas, or at anchor- the extra bouyancy keeps the bow from stuffing and the green water outta the boat.
No?
Ahhhhh.....
Another good question! That's what I love about this place. Smart people who love boats. Smart people ask good questions.
Let's look at what a boat designer/naval architect is trying to accomplish in an offshore capable boat's bow:
1) The finer (or slimmer) the boat's bow (or entry) is at the waterline the more efficiently and smoothly the boat will "cut" waves. I think that we would all agree that this is a desirable thing. Imagine being in 4'-6’ seas in a landing craft - miserable.
2) A boat with a fine entry will take less power to push and/or achieve higher speed for a given power. Again, I think that we would all agree that these are two items most of us would value.
So with these two preliminary needs you would end up with a boat that looks like this:
or like this:
These are called VSV's for either Very Slim or Very Slender Vessels. They punch though waves rather than ascending and descending waves. With all the discussions here on THT about bottom shapes (24 degree deadrise vs 22 degree deadrise) one would think that good riding boats are all about the bottom. One could make a 0 degree deadrise VSV that would be 10 times smoother than a Regulator (or Rock Salt).
So why don't we see VSV fishing boats from Contender? Why don't we see VSV family boats from Grady-White? Well......
VSV's have a problem. The have very, very little reserve buoyancy in the bow. (You are absolutely right!) What do you think would happen driving that second boat down a monster 20' swell at 60 knots when you reached the bottom?
Here's a video of another boat with very little reserve buoyancy in the bow:
To get more reserve buoyancy one "flares" out the sides. The flare can either Be a straightline (Rock Salt/Jupiter/Intrepid) Concave (Regulator, Yellowfin, Pursuit) or even Convex (Boston Whaler). By making that flare concave (Carolina) one can keep that slimness higher up the side while still ending up with a greater about of reserve buoyancy at the “top”.
This is especially helpful in semi-displacement or full displacement hulls as in both hull forms you are constantly asking the bow to take on waves. You need the slimness (low) afforded by that concavity.
So why not do it on all boats (Including the planning hulls popular here on THT and the Rock Salt)? Well...
As with all boat design elements Carolina Flare has a give-and-take aspect. When you make those bow sections concave you are loosing a lot of interior volume. The step-up in a Regulator's deck is a direct result of that concavity. The boat is so narrow at the designed waterline (or just above) that the foredeck would be just about unusable - tiny, cramped - yucky. Lou Codega, who designed the Regulator then must have said to himself well we'll bring the boats sole (deck) up here where there is more horizontal space! A great solution except that many, many fishermen object strenuously to a step-up in the deck. Your running from bow to stern with your first giant bluefin hook-up and you take a digger halfway and throw your Penn 130 into the drink - arrrrgh.
Secondly (and directly related to your question) you will have LESS reserve buoyancy in the bow that in a boat with straight flare.
So Carolina Flare has less buoyancy than if you drew a straight line from the gunwale edge to the chine.
So what about Carolina flare being drier?
For most wave/boat impacts the planning hull is throwing water off to the sides about midships. We can certainly all agree that Carolina flare serves no purpose here – correct? – It’s sticking out of the water ahead of the spray…
Now it gets nasty and the bow is plunging and slamming into the toughs. The water is ascending the boats sides and exiting at the gunwales. On a boat with Carolina flare that exit angle will be somewhat less than on boats like the Rock Salt, Jupiter or Intrepid.
The argument goes that because that angle is lower you will remain “drier”. The obvious answer is “Yes”.
But how much drier? I don’t want to stay drier on a boat I want to stay DRY! If you give me a boat that puts 10% less waves in my face I suppose I’d be less annoyed but I’d still be damn wet!
I have always said that if you want to stay “dry” on a boat you have to be under /behind cover. Period.
Instead of doing the conventional “T-Top” I came up with this:
I’ve been out in the middle of the winter here with freezing spray coming aft and the whole top covered with ice and remained “Dry” “Un-wet” “Waterless” “Without Moisture”!
The top makes you no hotter in the summer, keeps wind noise away from you and rain out of your face! Dry means dry – not drier than the guy in the other boat!
I can’t believe how many 150K Center Console boats I see (including ones with beautiful Carolina flare) that immediately put on a cheap piece of plastic across the front as a wind/waterbreak.
Carolina flare and plastic sheet:
To me that is a design failure. If I bought a 150K sportscar and had to have a guy at the canvas shop screw snaps into the boat to then accept plastic windows I'd be Pi&$ed.
Now I don’t mean to offend anyone but I get frustrated with the Carolina flare = dry argument. Its always taken as a matter of faith and yet almost every boat I see has a plastic curtain (which never gets removed - btw).
Again, dry on a boat means protected and protected means glass/metal/fiberglass – even plastic sheeting!
I hope that I’ve answered your question with my humble thoughts and, again, apologize to anyone who I might have offended.
BTW – I think that BW is coming over to my side on the t-top issue:
__________________ Jay Perrotta, President
Rock Salt Alloy Boats, LLC
PH: 207-400-7404 jay@rocksaltboats.com
I think the comments about developable (ruled) surfaces on boat bottoms (below the waterline) may be correct, but not on the topsides.
Just because a boat does not have a dramatic Carolina flare, does not mean the surfaces are single order curvature-most, if not all are not, and are in fact complex curvature from the chine to the rubrail. Now I have not taken a straightedge to every boat made, but here is a picture of a representatative example, the Bahama 41, that I pasted from their website:
You can see the bottom running surfaces are indeed ruled (note the straight section lines) but the topsides from the chine to the rubrail are most certainly not, as can be seen from the CURVED section lines in the bow area. This is typical of most Jupiter, Venture, Intrepid, etc, etc boats- and it’s done for a reason- and it isn’t dryness.
On the subject of ruled running surfaces and Carolina boats, here are a couple of shots of a cold molded boat currently under construction in Wanchese (54’ Ritchie Howell). Note the flair in the bow, but also note the bottom, it also is compound curvature, except for the area back by the transom. These surfaces are very complex, and work together to give the boat its characteristic soft (and DRY) ride. The comments about buoyancy are correct, but the dramatic flair is designed to give non-linear buoyancy, which is to say the forefront is narrow and presents a small(ish) footprint when running normally up sea, but if you hit a big one, the extras buoyancy kicks in at the last minute to prevent taking a green one over the bow. So the buoyancy may be less in total than a slab sided vessel, but it comes into play at a different point and is more useful than not having flair. This is called reserve buoyancy.
Look at the area on the bottom just under the chine in the picture above. You can see it is quite complex, and remains so until it fairs aft towards the transom. The picture below is from the same hull as the one above, and clearly shows the flat ruled area by the transom. There is nothing about any of these surfaces that is done to ease manufacture, it's all about water flow.
I think the dryness issue has little to do with why the flair is there in the first place, although it makes a nice story.
I totally agree with the comments on better enclosures needed for center consoles, I’d sure like to see more windshields and better designed enclosures to keep warm and dry, as it would really extend the utility of our boats.
Jay the enclosed helm station may be great for the northeast but here in Florida I think you will find it tough trying to convince guys that being in a glass/plexi enclosed station during the summer is the way to go.
[quote]blacklabmarine - 1/12/2009 1:53 PM
I have always said that if you want to stay “dry” on a boat you have to be under /behind cover. Period.
Instead of doing the conventional “T-Top” I came up with this:
I’ve been out in the middle of the winter here with freezing spray coming aft and the whole top covered with ice and remained “Dry” “Un-wet” “Waterless” “Without Moisture”!
The top makes you no hotter in the summer, keeps wind noise away from you and rain out of your face! Dry means dry – not drier than the guy in the other boat!
I can’t believe how many 150K Center Console boats I see (including ones with beautiful Carolina flare) that immediately put on a cheap piece of plastic across the front as a wind/waterbreak.
Carolina flare and plastic sheet:
To me that is a design failure. If I bought a 150K sportscar and had to have a guy at the canvas shop screw snaps into the boat to then accept plastic windows I'd be Pi&$ed.
Now I don’t mean to offend anyone but I get frustrated with the Carolina flare = dry argument. Its always taken as a matter of faith and yet almost every boat I see has a plastic curtain (which never gets removed - btw).
Again, dry on a boat means protected and protected means glass/metal/fiberglass – even plastic sheeting!
Glad you like the boat – thank you. My reply was written quickly and as I had a lot to say I might not have been very clear. I’ll respond to your thoughts….
Quote:
I think the comments about developable (ruled) surfaces on boat bottoms (below the waterline) may be correct, but not on the topsides.
I didn’t really discuss bottoms as the original post was about Carolina flare. The first poster asked about flare’s necessity vis-ŕ-vis dryness and the second about flare's effectiveness vis-ŕ-vis buoyancy. My post was about broadsides only.
Quote:
Just because a boat does not have a dramatic Carolina flare, does not mean the surfaces are single order curvature-most, if not all are not, and are in fact complex curvature from the chine to the rubrail. Now I have not taken a straightedge to every boat made, but here is a picture of a representatative example, the Bahama 41, that I pasted from their website:
You can see the bottom running surfaces are indeed ruled (note the straight section lines) but the topsides from the chine to the rubrail are most certainly not, as can be seen from the CURVED section lines in the bow area. This is typical of most Jupiter, Venture, Intrepid, etc, etc boats- and it’s done for a reason- and it isn’t dryness.
I certainly wouldn’t argue that the above pictured boat doesn’t have concave sides – it’s obvious (and quite pretty!). There are other builders who use even less flare and some quite slight (Pursuit, for example). I was using examples of boats that have no flare. Whose sides are developable surfaces as measured by me personally including both Jupiter and Intrepid (A disclaimer: both the Jupiter and Intrepid broadsides have minute deviations from purely developable but it is clear that they were designed with straight section lines and that the deviations are from building vagaries and not design.)
Quote:
On the subject of ruled running surfaces and Carolina boats, here are a couple of shots of a cold molded boat currently under construction in Wanchese (54’ Ritchie Howell). Note the flair in the bow, but also note the bottom, it also is compound curvature, except for the area back by the transom. These surfaces are very complex, and work together to give the boat its characteristic soft (and DRY) ride.
The boats pictured are semi-displacement boats and not very analogous to our discussion. As we were not discussing bottom shapes I’ll pass on this part of your post only adding that I know of no production fiberglass builder of planing hulls that is producing bottoms that have compound curvature like the one pictured. Not one.
Quote:
The comments about buoyancy are correct, but the dramatic flair is designed to give non-linear buoyancy, which is to say the forefront is narrow and presents a small(ish) footprint when running normally up sea, but if you hit a big one, the extras buoyancy kicks in at the last minute to prevent taking a green one over the bow. So the buoyancy may be less in total than a slab sided vessel, but it comes into play at a different point and is more useful than not having flair.
You are correct that the carolina flare gives a boat non-linear buoyancy but are incorrect in your conclusion of the non-linear buoyancy's effect. The flare gives less buoyancy (and less drag) at any point at which a wave impacts the stem. A boat with carolina flare reaches its own maximum buoyancy at the gunwale but not more than a boat with developable sides (which also reaches its maximum buoyancy at the gunwale). The carolina flare's advantage (useful in displacement and semi-displacment boats) is its reduced drag (resulting in less buoyancy) mid-stem.
Quote:
This is called reserve buoyancy.
Reserve buoyancy is all of the boat above the waterline and has nothing specifically to do with carolina flare other than the fact that a carolina flare boat has less of it for a given side height.
Quote:
Look at the area on the bottom just under the chine in the picture above. You can see it is quite complex, and remains so until it fairs aft towards the transom. The picture below is from the same hull as the one above, and clearly shows the flat ruled area by the transom. There is nothing about any of these surfaces that is done to ease manufacture; it's all about water flow.
I must be seeing the pictures incorrectly. The top photo has a definite convexity to the bottom while the below photo seems full developable. As I mentioned above this discussion was not about bottoms and the bottom in the top picture represents no production planing boat I know of. It would be a b@#tch to get out of a mold!
Quote:
I think the dryness issue has little to do with why the flair is there in the first place, although it makes a nice story.
Here you and I are in complete and utter agreement. In agreeing with me you are in a very small minority, though. Showing boats at boat shows with no Carolina flare dooms one to an endless stream of “Must be awfully wet with no flare…” statements. I've never had a single individual ask about buoyancy - not one.
Boat company websites and boat reviews are full of flare=dry statements:
MJM “…MJM 34z’s bow flare, apart from directing airflow out and away from the pilothouse and cockpit, works its magic with spray and waves, keeping guests dry”
This one might be true as the boat not only possesses flare but also magic - you can't argue wih a brochure that promises magical air and water manipulation....
Scout “The revolutionary hull combined with the bow flare assures a very dry and exceptionally smooth ride.”
Typhoon “…a fine entry forward, sufficient bow overhang (produces bow flare for a dry boat)…”
Offshore Magazine review of the Regulator 29’ “…and the significant flair forward will keep the boat dry offshore…” This one's doubly good in that the author/reviewer also incorrectly spelled "Flare" or maybe he was saying that the boat had buttons and Gizmos on its boat like a waiter at TGIFridays....Flair!
Marlin Magazine review of the Jarret Bay 32’ “…The bow flare not only gives her the dry ride shared by her larger sisters, but it also frees up a good amount of space for the walkaround deck…”
In my humble opinion the flare is there because it’s damn pretty. Nothing wrong with that at all. Builders took a well-known and desirable mid-sized boat design feature and incorporated it downward into planning hulls. It looks like it will throw water out at a lower angle than a straight sided boat so it must be a "dry" design element!
Lastly, I am not foolish or stupid enough to not understand that there are some planing boats that are drier than others. I would argue that the first and foremost predictor of a dry ride is a competent and experienced driver. Then the right combination of weight, width, chine flat, center of buoyancy and trim. Some boats do it well and some do it poorly. Ie: a skinny, small chined boat with too much forward weight will be way wetter than a wide hulled, properly chined boat in balance.
I hope that my tone has not been too aggressive or harsh. I’ve enjoyed your posts over the years and respect you highly. You own a great, and I mean great, boat. I just seem to have a little problem about the flare/dry canard. Give me an open boat between 20’ and seas big enough to plunge the boat’s bow and I’ll get you wet. Easily. I’ve been offshore in 50 knot winds and 25 foot seas – dry means protected!
Quote:
I totally agree with the comments on better enclosures needed for center consoles, I’d sure like to see more windshields and better designed enclosures to keep warm and dry, as it would really extend the utility of our boats.
I see that Oceanluvr has also replied on this while I was writing – I’ll answer you both!
Again, nothing but respect.
__________________ Jay Perrotta, President
Rock Salt Alloy Boats, LLC
PH: 207-400-7404 jay@rocksaltboats.com
Jay the enclosed helm station may be great for the northeast but here in Florida I think you will find it tough trying to convince guys that being in a glass/plexi enclosed station during the summer is the way to go.
I know that you are right that I will find it tough. We do t-tops as well...
Funny thing, though. The boat pictured was sold to a charter captain on Amelia Island, FL.
Jay the enclosed helm station may be great for the northeast but here in Florida I think you will find it tough trying to convince guys that being in a glass/plexi enclosed station during the summer is the way to go.
This is not a Florida boat, but trust me... these guys would be the first to tell you that the semi-enclosed helm is not hot in the summer. In fact, the shade afforded by the top makes the area underneath much cooler than being in the sun.
Looking through glass rather than plastic is an extra bonus.
__________________ .
Capt. Kevin ~~~~~~~~~~><((((*>
Jay us guys in South Florida consider Amelia Islanders to be Northerners
Not saying there are not those that may like the enclosed helm station in Florida but the weather is rarely as gnarly as you Northerners have to contend with. I would bet the vast majority of boats you see with curtains, and there are not many of them, are what we call snowbirds spending the winter in Florida before heading north for the summer. Once you are in production would be nice to see a Southern version of RockSalt IMO...
Quote:
blacklabmarine - 1/12/2009 8:56 PM
Quote:
oceanluvr30 - 1/12/2009 9:25 PM
Jay the enclosed helm station may be great for the northeast but here in Florida I think you will find it tough trying to convince guys that being in a glass/plexi enclosed station during the summer is the way to go.
I know that you are right that I will find it tough. We do t-tops as well...
Funny thing, though. The boat pictured was sold to a charter captain on Amelia Island, FL.
Jay us guys in South Florida consider Amelia Islanders to be Northerners
Not saying there are not those that may like the enclosed helm station in Florida but the weather is rarely as gnarly as you Northerners have to contend with. I would bet the vast majority of boats you see with curtains, and there are not many of them, are what we call snowbirds spending the winter in Florida before heading north for the summer. Once you are in production would be nice to see a Southern version of RockSalt IMO...
I was going to ask if you meant Amelia when you said people in the Northeast!
I can be stubborn and sometimes (if my kids are to be believed) stupid. Not only are the vast, vast majority of boats sold in Florida boats whose helms are open to the elements but here in the frigid and "gnarly" northeast the same remains true.
I've banged my head against the enclosed t-top for twelve years when one day as I was looking out my office windows at the Pursuits and Regulators for sale here at the marina where I rent space for the sales office it occurred to me that although I might sell enclosed helms people BUY open helms!
The Rock Salt helm is open. I have capitulated. I'll offer an enclosed version but the standard boat will be open. If requested I will hang isinglass and canvas with snaps! One goes against a market at their peril.
__________________ Jay Perrotta, President
Rock Salt Alloy Boats, LLC
PH: 207-400-7404 jay@rocksaltboats.com
As always Jay, thanks for your detailed reply. I think it would be bad form on my part to derail this thread with any more commentary, as it is really about introducing the Rock Salt 34’, which looks to be a fantastic boat, but I will clarify my comments and then desist.
- The discussion of (developable) bottoms was introduced back on page 1 of this thread, and I am continuing to add to this dialogue with my more recent post.
- I don’t know what “broadsides” are, but topsides, according to the Nautical Dictionary, are …….”the side area between the waterline and the deck”.
- Although I have not taken a rule to a Jupiter or Intrepid personally, I have seen lines drawings, and my recollection is that the forward TOPSIDES are (slightly) curved in two directions, subtle, but intentional, as are most FRP boats in this class. This occurs in the FWD area of the topsides, from the forepeak aft about 4’-6’ where the ruled surface “swarfs” around up to the tip of the bow. The rest of the topsides look to be ruled (for these two examples). There are good reasons for this, it is easy to make a mold with compound contour, and you get additional panel rigidity by using compound surfaces, which saves weight and gives a stiffer structure.
- The cold molded Carolina boat pictured has a cruise speed of 34 kts, and a top speed over well over 40kts. Semi-displacement hull?
- Most of the bigger FRP sportfish boats (Viking, Hatteras) use compound contour on specific areas of the bottom (and of course of the topsides). Every boat with prop pockets has compound contour, and many (most?) have compound contour in the forefoot area, below the waterline.
- I think we are saying the same thing regarding Carolina flare and non-linear buoyancy-my conclusion of the effect of this is exactly the same as yours.
- We disagree on the point of bow flare being cosmetic. I contend it is functional, by presenting the small(ish) footprint to the headsea, you get less drag and a better ride, the real reason for bow flare. The upper flare out provides much needed lift (buoyancy) when it’s really needed, to prevent the bow from being buried in big seas- a pretty elegant solution if you ask me. This point is pretty important, perhaps we could take a more detailed discussion to another thread? Particularly concerning ride quality?
- The cold molded boat loft surface pictured has no reverse draft (which would make de-molding difficult) other than the spray rail. If this were to be realized in FRP, you would make some concessions to the spray rail in the forefoot area to make the part “pullable”. Other than that, no reason why this could not be molded in FRP.
My point to all this is a disagreement (on my part) with the contention that somehow simple ruled surfaces are all that’s needed for best in class planing hull performance- be it below the waterline, or on the topsides. I know it’s possible to create decent boats with ruled surfaces everywhere, but I consider this a disadvantage, and a concession to (metal) manufacturing - a fact the Carolina guys have been schooling us on for many years.
Best of luck with the 34’-it’s truly a fine looking vessel.
RE: Rock Salt 34' by Black Lab marine 
