Pilothouse Skiff - sketches

[CaptChap]

Sorry but I didn't sucessfully attach the drawings I wanted to share -

[willin woodworks]

Topheavy?

[TerryLL]

Likely to ride bow up when planing and pounding in anything but flat calm.

[koederfischgriller]

No way!
Hull is way to small for that Cabin.
Take a look at Downeast Bassboats. Standing Headroom under folding Bimini/Dodger.

[CaptChap]

Thanks for all the comments! The hull bottom is actually flat in the aft bottom, from the just forward of Bmax back to the transom, with a slight rocker forward of only 5" or so. I built a scale model to work out this shape. It is not like the old "Brockway" styled skiff. which have dory-shaped rocker longitudinally throughout the run of the bottom. The flat-aft/rocker forward shape was achieved by cutting the side panels with a concavity in the bottom panel,which forces the bottom section flat in the aft section as the sides are bowed out when assembled. I'm probably not describing it adequately, but Walter Baron should be credited for this concept, and there are lots of his boats out there with happy owners using them.
As for the fore/aft trim, that should be optimized by weight distribution (i.e. not too much heavy gear forward). FYI, there is a great short video by Mark Vickers on YouTube showing one of Walter's skiffs running at full speed WOT, in a light chop ("Building the Lumberyard Skiff - How it Performs on the Water").

[SKIP KILPATRICK]

Looks like a nice dory-skiff to me. I image it would defy expectations as such dories always have.

[CaptChap]

No way!
Hull is way to small for that Cabin.
Take a look at Downeast Bassboats. Standing Headroom under folding Bimini/Dodger.

I actually did look at many small Downeast designs (including the Bass boat style) before I came up with this design.
I am aware that conventional design wisdom says that a standing headroom pilothouse should not be used on any hull under 25 ft LOA, more or less, but, hey, I like thinking outside the box, and that's why I'm building it my way. I spent many hours drawing different profiles, and many spreadsheets calculating hull displacements, immersion values, surface areas, etc., before I came up with this design. If it doesn't look good in real life, then I'll take full responsibility for the results. But I'm just a student of all this stuff; not an expert.
Thanks for your comments; that how we learn!!

[CaptChap]

One of my previous builds. I co-designed this boat with Lee Creekmore, many years ago, and it was pretty successful in off-shore racing in Florida/Bahamas waters. Sorry for blasphamy; it was/is a solid fiberglass hull (but did have a wood interior!)

[SKIP KILPATRICK]

your design does not look dissimilar to

https://www.boatbuildercentral.com/p...at-plans-hm19/

Although the Harbor Master may have more of an upturned bow.

[CaptChap]

One of my previous builds. I co-designed this boat with Lee Creekmore, many years ago, and it was pretty successful in off-shore racing in Florida/Bahamas waters. Sorry for blasphamy; it was/is a solid fiberglass hull (but did have a wood interior!)

your design does not look dissimilar to

https://www.boatbuildercentral.com/p...at-plans-hm19/

Although the Harbor Master may have more of an upturned bow.

Yes, you are correct, Skip... That was one of the many designs that influenced my thinking. I realize that it may not be for everybody, but the reasons I chose to go with the flat bottom is that (1) is is VERY easy, cheap, and fast to build; and (2) it doesn't require a big, expensive outboard motor to drive it, vs. a deep-vee hull of similar size.
For several years in the Bahamas I had a nice 20 ft. Sea Hunt center console boat which I enjoyed very much. It was a dream to drive, even in heavy chop. It did, however, have a 115 HP 4-stroke engine to push it (the "experts" said it needed a 150). This little skiff should be quite happy with a 40-50 hp, motor, which is a LOT cheaper to buy & operate.

[SKIP KILPATRICK]

Funny, I had a 20' Sea Hunt dual-console I loved that boat. And yes it had a 150 2-stroke and a 65 gal tank. That would be a beast at the gas pump even back then... now ugh!

I am certainly happy to sacrifice speed for efficiency these days. My current boat has a 20hp Suzuki and can run all day on 3 gallons.

[Peerie Maa]

I actually did look at many small Downeast designs (including the Bass boat style) before I came up with this design.
I am aware that conventional design wisdom says that a standing headroom pilothouse should not be used on any hull under 25 ft LOA, more or less, but, hey, I like thinking outside the box, and that's why I'm building it my way. I spent many hours drawing different profiles, and many spreadsheets calculating hull displacements, immersion values, surface areas, etc., before I came up with this design. If it doesn't look good in real life, then I'll take full responsibility for the results. But I'm just a student of all this stuff; not an expert.
Thanks for your comments; that how we learn!!

Did you calculate the range of positive stability taking account of wind loading?
Stability will reduce rapidly when a chine comes out of the water.

[koederfischgriller]

The flat Bottom is not a Dealbreaker at al to me. You might think of a Daggerboard for low speed manoverability and "counter Windage".There is a Youtuber who has one in his Power-Dory. Oregon Oldtimer is his Name i think

[Autonomous]

To please the eye, it needs to be stretched at least 10% to lessen the visual impact of the house.
If you are going to the effort and expense of building her, a small amount of V is only a couple percent more work.
I had a 22' C-Dory with a warped bottom and 5° deadrise at the transom. It was still harsh in any kind of chop.
I suggest you reconsider the flat bottom.

[koederfischgriller]

Stay flat, or switch to a Tolman Skiff. Adding the slightest bit of V makes a big difference in terms of effort

[CaptChap]

Funny, I had a 20' Sea Hunt dual-console I loved that boat. And yes it had a 150 2-stroke and a 65 gal tank. That would be a beast at the gas pump even back then... now ugh!

I am certainly happy to sacrifice speed for efficiency these days. My current boat has a 20hp Suzuki and can run all day on 3 gallons.

Skip - That's precisley why I'm going with this boat; I can't afford those expensive powerplants any more. I could actually use a 25 hp on this, if I didn't mind slower cruising speed. Even then it would be faster than an 18 ft. sailboat! And when the weather looks questionable, I'll stay in my recliner and read Wooden Boat Forum!

[CaptChap]

The flat Bottom is not a Dealbreaker at al to me. You might think of a Daggerboard for low speed manoverability and "counter Windage".There is a Youtuber who has one in his Power-Dory. Oregon Oldtimer is his Name i think

Interesting! I am actually putting an external keel running down the centerline, but more for grounding & trailer protection than for directional stability (however it may add a small amount of that, as well). It's a 2x6 CVG fir keel encapsulated in xynol/epoxy. That stuff is tough! (It's been dubbed "poor-man's kevlar). The hull is already encapsulated in that as well.

[CaptChap]

To please the eye, it needs to be stretched at least 10% to lessen the visual impact of the house.
If you are going to the effort and expense of building her, a small amount of V is only a couple percent more work.
I had a 22' C-Dory with a warped bottom and 5° deadrise at the transom. It was still harsh in any kind of chop.
I suggest you reconsider the flat bottom.

I understand your comments, and am well aware of the performance constraints of my design. However, this hull is already built, and I'm looking forward to using it as built, limitations and all. If I had wanted to build a Vee-bottomed boat, or a deadrise boat, or a dutch double-ender, I would have, but this time I wanted to to build this design. I have a bit of experience at sea, both under power and sail, and some experience designing, building, and repairing boats. Thanks!

[CaptChap]

Did you calculate the range of positive stability taking account of wind loading?
Stability will reduce rapidly when a chine comes out of the water.

Nick - A good idea, but, no I haven't done those calcs yet. Been too busy sanding & fairing! As soon as I get around to it, I'll post them. Based on my experience with similar-sized boats with large bimini tops, the biggest problem is when docking in a cross-breeze. I am however, installing built-in foam floatation to meet USCG regs. Thanks for the comment.

[Autonomous]

Ah, the build is progressing, good for you. The fine bow will help, my C-Dory had a rather full bow.
Docking in the wind is tricky with these boats, I could have used a daggerboard or leeboard a few times.

[John Meachen]

I may well be wrong but I have a strong feeling that the curve of areas will be much fuller at the stern.Which makes me imagine a lot of green water climbing over the bow,unless a bit more flare is worked in.

[CaptChap]

I may well be wrong but I have a strong feeling that the curve of areas will be much fuller at the stern.Which makes me imagine a lot of green water climbing over the bow,unless a bit more flare is worked in.

Yes, John, the beam is carried much more aft than forward, and there is considerably less volume in the forward sections. Because of this, I will initially launch her without any house structure, and test (with weights) the optimum placement of any planned structures. Bear in mind that the weight of a 40-50 hp outboard, a 8" jackplate, 2 fuel tanks, and the batteries, will be aft of the longitudinal CL, and the crew (probably only me and an occasional friend) will be somewhat near the CL. I plan on positioning very little forward, and probably even stow the anchor in the cockpit, ranther than forward. Also, I plan on installing substantial sprayrails (not shown) on the forward bow, as well, to help with any spray.
Since this is only a simple lumberyard skiff built of flat plywood panels, the addition of any topside hull flare forward (i.e. "Carolina flare") was way beyond the scope of this simple project. As I stated previouslly, I have owned (and enjoyed) a great 20 ft. center console (Sea Hunt 202 Triton) that had plenty of bow flare, and it was very dry, even in nasty seas. I also fished it many miles offshore in the Atlantic, off the Bahamas, and always felt safe. HOWEVER - this little skiff will never venture beyond the protected inshore bays & coves around Jonesport Maine, and only in the usually flat summer. Thanks for the comments... keep 'em coming!

[CaptChap]

Yes, John, the beam is carried much more aft than forward, and there is considerably less volume in the forward sections. Because of this, I will initially launch her without any house structure, and test (with weights) the optimum placement of any planned structures. Bear in mind that the weight of a 40-50 hp outboard, a 8" jackplate, 2 fuel tanks, and the batteries, will be aft of the longitudinal CL, and the crew (probably only me and an occasional friend) will be somewhat near the CL. I plan on positioning very little forward, and probably even stow the anchor in the cockpit, ranther than forward. Also, I plan on installing substantial sprayrails (not shown) on the forward bow, as well, to help with any spray.
Since this is only a simple lumberyard skiff built of flat plywood panels, the addition of any topside hull flare forward (i.e. "Carolina flare") was way beyond the scope of this simple project. As I stated previouslly, I have owned (and enjoyed) a great 20 ft. center console (Sea Hunt 202 Triton) that had plenty of bow flare, and it was very dry, even in nasty seas. I also fished it many miles offshore in the Atlantic, off the Bahamas, and always felt safe. HOWEVER - this little skiff will never venture beyond the protected inshore bays & coves around Jonesport Maine, and only in the usually flat summer. Thanks for the comments... keep 'em coming!

CORRECTION: Sorry - I meant to say "longitudial center of buoyancy" above.

[CaptChap]

Ah, the build is progressing, good for you. The fine bow will help, my C-Dory had a rather full bow.
Docking in the wind is tricky with these boats, I could have used a daggerboard or leeboard a few times.

Hey Autonomous, Thanks. Actually I quite liked the way the C-Dory fit a very usable pilothouse onto their hull, and it was one of the reasons I started looking into something similar on my little skiff. I understand the limitations on comfort in a chop, but still those boats have satisfied a lot of folks who cannot afford (or do not want) anything bigger. Cheers!