Custom 19' all weather, minimalist, strip plank composite 'go fast'

Discussion in 'Boat Design' started by socalspearit, Sep 2, 2021.

  1. fpjeepy05
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    fpjeepy05 Senior Member

    The burden of safety is on the manufacture. When a boat is "home made" the state is supposed to "inspect" when they issue hull id numbers. Usually they don't do much.
     
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  2. fallguy
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    fallguy Senior Member

    You are acting like we are hurt. I assure you that is not the case.
     
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  3. socalspearit
    Joined: Apr 2021
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    socalspearit Junior Member

    Well, lots of acrimony here, but thank you to everyone who gave me feedback. It was very constructive and useful regardless of if it's positive and negative. Right before I started this thread, I had built my strongback, cut sections, laid them out and for the first time was seeing it real world to scale when I said 'hmm, not so sure... I shouldn't make this hull without having a better idea of the end result...' The design process feels much more finished now.

    I would honestly love to mess around with cat hulls and tunnel hulls--I studied them and on paper 100% see and understand potential advantages but the majority of my experience in these waters is with a very different shape and style, and my window to put this together is within the next five months, so not much time for hull experimentation.

    There are 100% standards in place for a '6 pack charter boat'. This question keeps coming up, I dunno why it seems hard for people to wrap their heads around, but perhaps I take a lot for granted here.

    In short, in most of the United States, ANYONE can operate and purchase pretty much ANY vessel for NON-COMMERICIAL use (like an 16 year old kid could for their first boating experience be behind the helm of a 1800hp 50' race boat). Some states may impose more regulations but most coastal states do not. California in the last year or two started phasing in a sort of very simple boating license that I think is like a very much watered down written driving test for young boaters. It never affected me because I got my commercial license prior to it's being implemented. I can't remember but I want to say it has many allowances that allow licensees to be grandfathered in without much hassle, etc, and in general I haven't heard that it is burdensome. At the same time, I think the state of California mandated also that for any recreational boat under 20' the operator must wear a kill switch lanyard which I honestly think is not a bad idea; all the crazy solo island runs I did in weather on my inflatable I was pretty religious about this and solo guys falling out of a boat mid-channel is one of the major ways guys like me die out here. There is no rule in California that lifejackets must be worn by adults, but I also am very adamant about being in a wetsuit on my boat, a lifejacket is not going to do much but make it easy to spot a corpse from the air since even in summer our water temps will kill someone in street clothes in probably less than 24 hours. The freediving wetsuit would keep me conscious and swimming for at least 24 hours in the winter. Our first responders on the water also know and appreciate this fact.

    Now, for any kind of COMMERICIAL USE, standards are different and most of it falls on the CAPTAIN. I am not sure if it's like this in other countries, but the US Coast Guard defines commercial use very broadly. If 5 guys go out on a friend's boat and they split gas, that does not count, but ANYTHING else does if there is money changing hands. A bit south of me there's a lot of guys operating unlicensed fishing charters, which basically means it's a guy who has not passed any of the USCG captain requirements is taking people out for hire on a boat not insured for commercial use. In the dive world it's common too-- a lot of instructors with a boat charge for a class and as part of the class take students out on their boat, and try to justify it as 'well, I'm not specifically charging a boat fee so we're just friends on my boat'. That does not actually fly per our law, and an insurance company would also deny coverage if there was a claim because they would go by the USCG definition of commercial use. I also know boat owners who DON'T want to have any kind of captain's license because they believe (for good reason) that it might open them up to liability if somebody gets hurt on their boat. That's not how I run my business.

    I am curious, in other countries, to be a 'charter captain' is there an actual federal requirement? For the basic USCG 6 pack license, the applicant must have 360 sea days, 90 of which have occurred in the last 3 years and be in the ocean (distance from shore varies depends of locality and I want to say a 'day' is 6 hours but time in the harbor does not ever count). Besides that there is a 4-6 hour written test covering safety, navigation, right of way, boat operation, which even people who have spent a lifetime on the water will need to study 30-100 hours in order to pass. Then there's a criminal background check, and a physical including hearing and eye exam. You have to have current CPR and basic first aid. You even have to sign an oath to effect of that you'll obey the law, etc. That's to commercially operate a boat with up to 6 passengers. For larger boats and more passengers the requirements are stricter, such as more sea days on large boats, more written testing, more physical stuff including a swim test.

    So, for a '6 pack' charter boat used commercially it must be run by a captain (or he/she must at least be onboard) who's met the requirements for a commercial license, and the boat must be legal to operate. For boats larger than 20' the USCG physically inspects the boat. For a boat smaller than that it just has to be legal to operate, which in my country means that it has proper nav lights, a safe fuel/engine system, horn, etc, I mean's a functioning and working boat and is registered and paid up with the Department of Motor Vehicles. For commercial use the only other requirement I remember is that you have a flares/signalling devices, radio, and a type 1 life jacket for all commercial passengers. For an inboard design I seem to remember you have to have a fire extinguisher, etc. I have to double check but if running a certain distance offshore you are required to also have a satellite tracker which most guys with any sense would have on their boat anyway. In short, to make a small boat LEGAL per USCG standards ALL the safety equipment falls within what most any experienced and responsible boater should have on board anyway. I of course have commercial insurance on my inflatable but if I remember correctly there isn't actually a federal law that mandates a boat used commercially must be insured for commercial use, although if you have a larger boat with employees, etc, then there'd be more requirements you'd utlimately need commercial insurance to meet.

    For 'backyard boats' the primary federal requirement seems to be that they have a VIN and label showing max weight, engine, etc. In an earlier reply I posted a link to the USCG guide for backyard builders which gets into how they want you to calculate maximum HP, weight loading, floatation requirements, etc. On small non-commercial boats this is honor system--it's on the builder to insure level floatation and do the calculations. And, you'll have to get registered with the DMV which is always harder if it's anything other than store bought (my inflatables have always been a project--I have to physically go to the office and stand in many lines, etc, can't just do it online). However, most boats on the water are of commercial manufacture in which case if they were made in the current century were almost certainly manufactured to ABCY standards, which are considerably more detailed than basic USCG standards but not idiot proof (ie the worst bow-rider designs can still pass these standards), and boats for commercial sale are also tested more extensively (ie truly flooded and required to demonstrate turning and manuverability, etc).

    Incidentally, while it is a HUGE market consideration for boat sales and charter operation there's nothing in the ABCY or USCG that mandates a boat cannot 'feel tippy' or 'keep the passengers dry' or have a certain 'beam'. In fact, it's quite the opposite--besides the obvious like nav lights and safe engine fuel system, they are concerned with float level if swamped at max capacity and that it not be overpowered (this is a function of steering system, bottom shape, transom height, and LOA * transom width). The better USCG guides for fishermen and noncommercial use go to great lengths to explain that the way the boat 'feels' when boarding or at rest has absolutely zero to do with ultimate stability or safety.

    This is my final design with true dimensions. I might move this topic to the 'build' section. I actually don't know anyone personally who's made a strip planked boat but the woodworking is not a big a deal for me (after a lifetime of Skillsaws and screws I finally learned real joinery building solid walnut furniture mostly for my wife's sake during 2020 quarantine), and while I haven't done a lot of glasswork I've been using all manner of marine resins and glues for years building custom dive electronics and have several friends who have done a lot of foam/composite work for marine and aviation. I do have some dumb questions though...

    My primary resources have been the Gougeon book, Building Strip-Planked Boats, and the youtube channel 'Tips from a Shipwright', as well as the articles on naval architecture calculations linked in previous posts. Thanks for sending me references and additional info to those who did, more good sources are very welcome.

    SpearIt_One_v5 v1-EXPLODED.jpg SpearIt_One_v5 v1-a.jpg SpearIt_One_v5 v1-b.jpg SpearIt_One_v5 v1-c.jpg SpearIt_One_v5 v1-d.jpg
     
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  4. fpjeepy05
    Joined: Jan 2010
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    fpjeepy05 Senior Member

    My brain wants that seat to be centered.

    Those renderings remind me a little of the MAC attack 360
    [​IMG]
     
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  5. socalspearit
    Joined: Apr 2021
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    socalspearit Junior Member

    Ah, that's an interesting boat.

    Visually, if I was making a boat to sell I'd put the seat in the middle. It'll sit perfectly level in the harbor, or when crawling through the harbor, and in a showroom look 'right' to most people. Operationally for the way I intend to use it it's better offset.

    1) since the boat is intended to be boarded from the port side the weight of somebody sitting slightly starboard makes it very stable for all involved and there is more floorspace for diver to flop into the boat 2) I didn't design trim tabs since I've never owned boat with them and I've never seen a small RIB with them (although on execution it may be necessary) and on my inflatable WOT the force of the engine wants to heel the boat slightly to PORT (edit: corrected from original post when I wrote starboard), so underway at speed I think balance would be better 3) offset makes it easier to get around the console to the bow 4) forward port stowage is intended for anchor (30lb kettlebell) and usually also collects dive belts and weights so can easily have 80lbs in it which will tend to balance the weight of a solo operator 4) returning from the islands in weather sea will usually be to port

    Based on the tests with the wood model the boat heels like 3 degrees or something minimal with the driver offset since the weight of that person is still well within the waterline footprint of the boat, although underway planing forces will certainly change that.

    Incidentally, although there could be a lot forces at work, the photo of the Mac 360 looks like the boat is heeling port? It would probably run more level if the driver was more to starboard.
     
    Last edited: Sep 26, 2021
  6. fallguy
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    fallguy Senior Member

    Last edited: Sep 26, 2021
  7. Mr Efficiency
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    Mr Efficiency Senior Member

    Oh well, I am probably just using as a frame of reference what would be allowed here, and there is not a ghost of a chance anything like that would be permitted to ply for hire, for the use mentioned. It would not be legal to carry six people in such a boat in open waters, for private use. And more importantly, would it be prudent to do so ? My opinion is no, and I don't care who here disagrees with that assessment. A lightweight boat that has very little form stability, loaded up with unfixed weights (people) that weigh as much or more than the boat, and to make matters worse, perched on a raised self-bailing sole, this is definitely a mix to avoid.
     
    Last edited: Sep 26, 2021
  8. fallguy
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    fallguy Senior Member

    The one thing the CG won't test in a one off is the one thing this boat would fail which is stability. The change and adding the floats may help, but..
    The real problem with a long, narrow hull and 60 hp hasn't even been addressed. Before delving into it, I challenge anyone on the thread to find a 4' wide boat 20' long with a 60 hp engine that isn't a sprint boat.
     
  9. Mr Efficiency
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    Mr Efficiency Senior Member

    I reckon I could make a reasonably seaworthy 20 foot x 4 foot boat, with a 60 hp OB, to carry say 500kg, but the first thing to scratch would be the self-bailing. Next to go would be the low bow.
     
  10. socalspearit
    Joined: Apr 2021
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    socalspearit Junior Member

    @Mr Efficiency The '6 pack' license means the captain is licensed to take 'up to 6 paying passengers' but that does not meant that the license gives carte blanche for that captain to put 6 passengers into any type of vessel whatsoever and run it however he/she wants in any kind of seas. My boat design would not be prudent to operate with 6 passengers because that would likely exceed the weight limit and they'd be sitting on top of each other or perched on the gunwales. I have stated that more than a time or two in this thread, which is admittedly very long.

    I think also again, you're not understanding my interpretation of self bailing. Not really sure what you'd call my design except maybe 'swamp at rest but self bail when underway'. The COG in this design with occupants is four or five inches off the waterline and it depends on planing action when underway to push it up out of the water and drain the deck unless loaded very light. Loaded at the weight limit the aft half of deck may be submerged until underway and planing action lifts the boat up and sucks the water out of it. Some of the small Zodiacs are designed this way, with a flooding 'subdeck' which makes the boat more stable at rest and which drains when the boat is making any kind of speed. They're also designed with a much higher COG but giant external floatation to compensate for the instability that brings. Again for my application I don't care if the cockpit is wet; we're swimmers in wetsuits who don't spend any time sitting in the boat when at rest, plus the deck if enclosed can quickly become a cesspool of piss, lobster parts, and fish slime, so I'd just as soon it wash off. With 17 cubic feet of foam below the deck, 18 gallon gas tank that will always be lighter than water also down there, and another 3 cubic feet of dry bilge, 3 cubic feet of airtight space in the nose, plus another 8 cubic feet of foam above the waterline it's fine. If you could make a 20' x 4' boat to these specs which is also DRY in weather I think you'd win some kind of naval design Pulitzer prize.

    The john boats that keep being mentioned I had to look up since I'm not familiar but yeah, those look awful; the deck is at the sheerline and guys are supposed to walk around the deck and cast standing up. The most basic physics and stability tests on my wood model show that to be horrendous; a light boat which is long and narrow will be VERY sensitive to COG. But if the deck is at most a few inches above the waterline and people are seated virtually on the floor it's very stable both in the tests of my model and thousands of hours in all weather on my inflatable. Putting in and out of the harbor I typically sit on the tubes for visibility but when actually underway we sit on the floor, putting us at most 3" off the waterline and COG below the sheerline of that boat.

    Umm, that's the point. I want a boat with speed potential and good seakeeping that doesn't cost $75k and burn 10 gallons an hour. A fast boat with an idiot or inexperienced operator behind the helm is a hazard to all. It's on the operator to operate the boat responsibly given the loading, passengers, and sea conditions. I am guessing you have ridden in a taxi before? If it was within the last 30 years that taxi had a top speed of over 100 miles an hour. Was it operated at that speed?

    More engine than needed provided it isn't too heavy is a plus with a small boat. Limping home in some weather on a 60hp engine is a better proposition than a limping 25hp. Per the USCG's own standards this slightly larger hull than my original design would be rated up to 70 or 75hp but for a minimal boat I want the power-to-weight of a 60hp.

    I whole heartedly agree initial transverse stability is less with a narrow hull but underway and in seas they're great and very stable provided COG is kept low. I have, ridden probably more often than I should have, in a gale or wind storm two inches off the waterline in a boat that's 15' long and less than 4' wide. I've been in the same conditions more than a time or two in a 'proper' fishing center console less than 20' also. That's why I'm happy with the long narrow boat for my application. It's not a fishing boat that needs to stop offshore and be a stable platform for guys to cast off with a beer in hand. It's not intended for standing operation. It's not a family boat for sale to general public. In most any seas it's slightly wet to soaking wet, but we're saltwater nuts in full wetsuits.

    Thanks for all the feedback but I need to unplug this stuff and get to work building.
     
  11. Mr Efficiency
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    Mr Efficiency Senior Member

    You seem an articulate and intelligent chap, socalspearit, which makes it all the more baffling why you are fixated on this type of vessel, but maybe it is all part of the "excitement" of getting out on the water for you, good luck with it, and don't forget to give a report on it.
     
  12. fpjeepy05
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    fpjeepy05 Senior Member

    The boat won't be stable. Everyone knows that. The owner/operator/builder knows that everyone will be laying on the floor at all times and that is the intended application. It will be fine for that application. How are you still missing this?

    Giesler Lake Nipissing - 18'x59"beam w/60hp does 27 knots. I wouldn't consider it a sprint boat. I agree 60hp is a little much, but so does socal. I think 40hp would be plenty. But if it's flat calm and everyone wants to feels scary fast go for it.

    Eduardono Durado 210 21'x52" beam w/25hp does 24 knots. Oh my lanta! He is standing! How dare he.

    Socal, stay on course. You have a good understanding of what you are doing.
     
  13. socalspearit
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    socalspearit Junior Member

    I am off, going fairly slow and working on transom and bulkheads since I realized that to do this right the bulkheads need to be as finished as possible so that they can be incorporated into the section guides and properly bonded to initial strips, and the first interior bulkhead also needs to have an airtight maintenance hatch, which will be easier to build before installation, so that is taking some testing--EPDM gasket material and router work.

    The transom is 3/4" marine ply laminated with 1/2" WRC plus a 1/4" cladding of white oak (bright finish) on the visible interior. First interior bulkhead is 1/4" marine ply laminated with 1/4" WRC, then the second bulkhead which is the fore wall of the cockpit and has openings for the forward hatches is 1/4" marine ply + 3/8" WRC cladd in 1/4" white oak (bright finish). I'm trying to keep the weight down as much as possible so I'm probably over-engineering with all the laminates but it's also a good opportunity to get more practice with these glues and resins used this way.

    Photos are the intended 'look' of the interior bright wood--natural WRC with black fairing in between for the visible interior hull (the final seams will not be as thick as this test section), and the bright finished white oak for decking and some of interior bulkheads, etc. The white oak is lightly dyed and hit with a dark gel stain prior to epoxy coating... I liked that look and then after the fact realized it's reminiscent of teak. The stains and dyes are rated for some UV resistance but I'm planning to do some generous coats of clear UV resistant urethane on everything.

    PXL_20211007_021613557.jpg PXL_20211007_153629265.jpg
     
  14. fpjeepy05
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    fpjeepy05 Senior Member

    I like the look. There is a product called Coelan that is supposed to get up to 10 years without requiring refinishing. I've never used it, but I am thinking about next time I need a varnish. It's pricey though. $365/gal.
     

  15. socalspearit
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    socalspearit Junior Member

    I looked up their website, and one of the articles which featured a test of the product against other sealants. Interesting, although I did notice on the article there was a dearth of higher end urethane finishes which all tend to cost in that neighborhood; Coelan was the highest rated but also the most expensive of those in the test. I am planning on Interlux two part urethane. It usually gets fairly good ratings for longevity when compared to others in its price point and I have a ton of experience with it from building very nice furniture. I've also used Bristol Finish, which in some tests was higher rated for longevity than Interlux, and in my experience a little less touchy when it comes to application. One caveat is I think the Interlux satin additive is much easier to work with than the Bristol satin. Coelan being a single part mix would be much simpler; Interlux, once you're mixing in the various satins and thinners can be quite a project--a 5 or 6 part mix that needs to be done with syringes and such for accuracy and spreadsheet for calculating precise amounts.
     
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