Johnnyfishes

Out of interest how much was this boat stretched by. Was it stretched in length alone and was it difficult?

This is amazing - thank you for looking into this and I hope it is of some interest to you as well. It is my intention that this becomes more than simply the academic exercise it is at the moment - I would love to build the first stretched OK24! As I said before it has always surprised me that offshore fishing boats which spend so much of their time trolling at this very inefficient 8 kt "hump speed" seem to have that so low on the list of "design priorities" - I guess when fuel prices were cheaper it didn't matter as much. Or perhaps when you factor in the typical usage - long runs off shore, bottom fishing, live baiting, slow trolling etc then trolling lures at this speed is not as much of a factor as I imagine. I know that we can use up to 3 times the amount of fuel in a day between live bait fishing/ slow trolling at say 4 kts and lure trolling at 8 kts when in a small "trailer" boat. Hence some of my surprise at the OB 20 numbers. I would love it if your OB 20 is as efficient at those speeds as the chart predicts but they seem incredibly good numbers. The steady increase in interest in Panga's for the recreational boater (in the US) may well be a reflection of people feeling the pinch of fuel prices but I also feel like their attributes as great all rounders have long been held back by their less than beautiful looks. There was definitely a time when I would have sworn I would never be arguing the merits of a Panga! I like the lines you have drawn a lot - and also that you have found a clever soln to the stretch - but I have a couple of questions: 1) I am curious how much you think the bracket helps enhance the waterline length/ efficiency at trolling speeds? Or whether this hull would perform similarly with transom mounted engines? I quite like being able to pass rods over engines that are closer to the boat when fighting a fish. I can see their advantages in increasing cockpit space and also as a boarding platform - but am curious if they improve hull speed as well? 2) Would/ could one increase the beam and possibly height of the flare slightly to give the impression of a "beamier" hull whilst maintaining the slim underwater profile - or does this enter the realms of a total redesign and/ or affect stability? I look forward to seeing some predictions when you get a chance. And once again many thanks.

Point taken regarding wind power and fishing! It has certainly worked for centuries! Also thank you for the chart. Am I interpreting it correctly in assuming that the 6.5 kt speed seems (to me) strangely efficient with a fuel burn of 13 nm/ gallon? (The whole boat seems very efficient in that case). From a fishing point of view, this boat would burn twice as much fuel in a day fishing at 9kts vs 6.5kts (albeit it’s still pretty good to do a 10 hr day trolling on 40 lts (vs 20 lts at 6.5 kts)) I guess the question I am asking is how that 6.5 kts efficiency could be pushed to a slightly higher speed. In marlin fishing there is a huge difference between 6.5 kts and 8/8.5 kts in terms of success and how well lures run etc. Would this hull stretched 25% in length only, and somehow keeping the weight similar, achieve this? In my terms I am measuring efficiency not as a measure of fuel burnt for a distance covered but in terms of maximising trolling time out of a certain amount of fuel at 8-9kts speed. (I do understand that this is a lighter hull design with a shallower deadrise than the OC series)…

From personal experience of 3 different types of boat I have fished in doing very similar outings - and repeated enough times in each boat to know that these numbers are "repeatable" ... a friend's 17 foot Mako with a 90 HP Etec averages 130 lts of gas burned in a day pulling blue Marlin Lures at 8-9 kts a 36 foot Hatteras (heavy and built in the 70's) with twin 300 HP diesel inboards burns about 220 lts of diesel, and a Yamaha Panga 23 with a 50 HP Yamaha 4 stroke will burn about 50 lts of gas in the same day. The Panga will almost always out fish the short "trailer boats" and will often do very well side by side the big "Sportfishing boats". I don't really have anything better to compare with than the above as to what a person's idea of fuel burn is, but logic would dictate that for the man not able to afford a large sport fishing boat, then all else being equal a Panga would be a better bet for trolling marlin lures than a short trailer boat. Beaching and other functions of a Panga aside, I am curious to know whether simply stretching an Ocracoke enough in length would match these sorts of differences in fuel burn. I still think a stretched and narrow Ocracoke would be prettier than a Panga!

Thank you for your very kind and detailed response. I suspect it must be frustrating as a Designer when some layman wants to start altering your carefully designed works of art! We typically would run for less that 1.5 hrs per day total and troll for 6 - 7 hrs at 8-9 kts - so any savings at that speed would be considered a real bonus especially with rising fuel costs. I have always been amazed by the amount of fuel that a small trailer boat can use at these speeds - when compared even to say a large (albeit diesel) inboard sport fisherman. I am no boat designer, but have often wondered whether a part of this is because a large sport fishing boat over say 36 feet is still within is "hull speed" at 8 kts; vs a trailer boat where you essentially are spending all day driving it "uphill" at those speeds! With this in mind, could I ask a couple more questions on this subject? 1) I understand that there are compromises on the weight as well that effect the efficiency - but would it maybe make more sense to stretch the OC 24 (not the OC 20) as much as structural/ aesthetic parameters would allow? Boat would typically have 4 men on board, with fishing gear, but minimal clutter. No head etc. 2) What would you Consider acceptable to stretch your OC plans by? Aesthetically, I feel like one could add 25% and still have a very handsome boat - far more beautiful than a Panga - that would still retain some "Carolina" lines. I don't know what you would consider acceptable from a structural/ design point of view? 3) Would you be comfortable "keeping a watchful eye" on a builder who did this having purchase the appropriate plans? 3) Is the "transom bracket" considered "free length for the weight" at displacement speeds ? In other words, were one to stretch a hull to the same length as a bracketed hull but keeping it "full" all the way, then would one then need to increase the scantlings/ structure of this hull - and thereby increase the weight and reduce efficiency? 4) Are there any major disadvantages (other than aesthetics) to a longer leaner hull that one is not planning to run at excessive speeds? (As I understand it many boats have evolved more beam to carry larger engines/ and or fit more amenities into a shorter hull). I guess what I am asking is, will a 28 foot boat with an 8 foot beam behave very differently in terms of stability/ planing characteristics than a 24 footer with an 8 foot beam? 5) Are there other "tricks" a designer could employ (as suggested by Oyster) that might trim the boat more level? Wider chine flats? A different hull form? The noticeable growing popularity of the Panga style hull in the US must speak something about the rising prices of fuel/ their sea-worthiness/ practicality - which it would seem poor third world fisherman have long known/ admired. I have never liked their lines, or low freeboard but have always been impressed by them as a fishing platform.

I love the look of the Ocracoke series/ Carolina hulls, but I am looking for a boat with as little "hump" as possible as the boat speeds up. The reason being is that I want a hull that is efficient at 8/9kts (this is a speed we troll lures at a lot) but I also want a boat that can plane/ rum some distance - though top speed is not particularly important to me. Say a cruising speed of 20kts or so and a max of 30. The closest hull that we have come across that can do this is a Panga style hull. A few questions: 1) Could Ocracoke series be stretched in length by a few feet (I am guessing by changing the spacing of the framing)... 2) Would this have a positive impact in the tradition between low speed and planing... and would the hull be more efficient at say 8/9kts... Again - top speed is not that important and neither is having more "beam" although at a certain point, I understand that the aesthetic of the hull as a "Carolina hull" would change ...

I have read somewhere that some production builders cross the port scupper inlet and let it out at starboard and vice versa. I assume the rational is that a heavy person in one corner actually raises the scuppers away from the water line and helps prevent water coming in, particularly in small boats where the margin between a self-bailing deck and the water isn’t massive. Is this recommended on boats such as the Ocracoke 20? Are there disadvantages to this system? More dangerous when the boat is swamped? How does on achieve the “crossing of the hoses” … must the outlet be lower than the inlet?