Deep vs Shallow Water Boats

[ghostdog]

Hello all,

I was searching, as usual, for plans for some future boatbuilging project. I already have two unfinished boats in the basement but from time to time I need to take a brake from building and dream of future projects. I have only built kayaks and canoes so far and I would like to try a moderately sized sailboat. I was looking in the 12-14 feet range and many of them are advertised as ideal for shallow waters. Obviously not any boat is suitable for everywhere. In my part of the world there are no shallow waters. We have some lakes but they are so small only for pirogues and canoes. The sea is deep, rarely calm and without tides. On every sailing book I have to skip 1/3 that is talking about tides.

So what is the difference in design of a shallow and a deep water boat? OK shallow draft and flat bottom would be nice for the shallows but what design features would be recommended for deep coastal sea waters?

[The Q]

Good freeboard, and a fixed lump of lead well below the water line to keep you up the right way.

[johngsandusky]

If you keep the boat at a dock or a mooring, a keel will provide more stability.

[ghostdog]

Traditional wooden boats here are round bottomed, carvel planked, permanently moored and weight more than a car does. All the others are plastic with outboards.
These traditional boats are not suitable for amateur boatbuilders, or trailerable.

[Peerie Maa]

Traditional wooden boats here are round bottomed, carvel planked, permanently moored and weight more than a car does. All the others are plastic with outboards.
These traditional boats are not suitable for amateur boatbuilders, or trailerable.

This is trailerable, and has the same general form as a Gaita.

So if you can find the plans of a small trad boat from your coast, you could easily build her strip planked, and use either beach stone in bags, or water in big cans for disposable ballast. I found this on an old thread.

Keyhavenpottered,

About the boats of 15 – 25 ft. (for boats more than 20 -25 ft. most of the fishermen interested for ‘trechantiri’).
There are 2 principal types of boats, with small miscellaneous changes, for open waters from 3,0m (10 ft) – 6,50m (21 ft), with or without sails, with or without engine, for fishing or transportation. The type of sail named ‘latini’ (latin sail).
1. ‘Gaita’ type (double ender). See typical Lines Plan. LOA 4,90m. B 1,60 m. H 0,60m.
2. ‘Papadia’ type (with transom). See typical Lines Plan. LOA 5,80m. B 1,70 m. H 0,65m.


For sailing boats with ‘latini’, the max. height of mast (above deck) must be the 2/3 of the LOA of the boat.The length of the antenna equal the LOA of the boat. The distance between the mast and the fwd end of the antenna is about the 1/3 – 1/3,5 of the length of the antenna. The distance between the mast and the stem is about the 34% - 38% of LOA.




Best Regards from Greece

[ghostdog]

So if you can find the plans of a small trad boat from your coast, you could easily build her strip planked, and use either beach stone in bags, or water in big cans for disposable ballast.

Has anyone done something like that before? Find the lines and offsets for an old design you like and actually build a boat?
The ballast will be needed to compensate for the weight difference. These old boats were really heavy.

[Peerie Maa]

Has anyone done something like that before? Find the lines and offsets for an old design you like and actually build a boat?
The ballast will be needed to compensate for the weight difference. These old boats were really heavy.

Yes of course, in the US, Norway, Denmark, the UK that I know of. They often do not need to change the construction methoda to reduce the weight, but as long as your shell and longitudianl structure scantlings are the same, you can as you realised use ballast to set her to her marks and for stability.

[Clinton B Chase]

Has anyone done something like that before? Find the lines and offsets for an old design you like and actually build a boat?
The ballast will be needed to compensate for the weight difference. These old boats were really heavy.

You will definitely want to make sure you have the knowledge and skills to do this so that you can do it well - if not, find a good designer/builder who can.

[ghostdog]

I always change a few bits in the boats I build, but I wouldn't build a whole boat without a proper plan. At least not yet.

[heimlaga]

Traditional wooden boats here are round bottomed, carvel planked, permanently moored and weight more than a car does. All the others are plastic with outboards.
These traditional boats are not suitable for amateur boatbuilders, or trailerable.

I rekon that traditional Greek boats are built the way they are for a good reason. Your sunlight is very strong and will dry out a boat quickly. Therefore carvel planking which can be recaulked is better than clinker which often cracks under such conditions.
A flat bottom really has no advantage on a boat that doesn't have to be hauled ashore on a sandy beach nor have to stay upright in a drying out mooring at low tide nor as to float in very shallow water. A round bottom boat is generally more seaworthy in the sort of crisscrossing short waves that I imagine there would be in the Greek archipelago.

However it should be possible to build a lighter round bottomed boat suitable for Greek conditions....... such boats do exist in various parts of Europe but they aren't very trendy at the moment.

[ghostdog]

However it should be possible to build a lighter round bottomed boat suitable for Greek conditions....... such boats do exist in various parts of Europe but they aren't very trendy at the moment.

You are right about the local conditions. Could you please give one or more examples of such boats?

[heimlaga]

You are right about the local conditions. Could you please give one or more examples of such boats?

What are you looking for?
Rowboat?
Sailboat?
Displacement motorboat?

-I come to think of Canadian Bush Island doubleenders and American peapods.
-A small slätbåt (a peculiar version of scandinavian doubleender smooth on the outside) of the type formerly built on the Finnish coast between Kristinestad and Björneborg could be carvel built or strip planked instead of the traditional half lap clinker. Their hull shape would not look foreign in Greece though the hull is longer in proportion to beam and depth.
-In Hälsingland in Sweden they built some very shapely and seaworthy strip planked double ended fishing boats starting in the 1930-ies. I wonder if drawings could be found.
-Stjernesnekke is an 18 foot norwegian double ended sailboat often carvel planked yet sometimes strip planked.

I am thinking about a boat that would be sort of related to the traditional double ended greek frishing boat but a bit lighter and sleeker and either carvel or strip planked.

[Michael_Owen]

It sounds like getting tossed about in a dinghy is going to be pretty "exciting" in your part of the world, if not downright stressful.
That said, round bottom, deep keel, and outside ballast would help. For an amateur, maybe the Haven 12.5. Quite advanced, complexity-wise, but well documented and with lots of folks around to help if you get stuck.

I'm sure others will be along with even more appropriate designs.

Good luck with your builds and your dreaming!

Mike

[Ian McColgin]

Assuming a mooring or dockage, the Haven or her older cousin LFH's Dough Dish would suit. Were you an experienced sailor I'd make the surprising suggestion of buying and restoring a wooden Thistle or such - many of those hot racers are actually plenty seaworthy if you stay alert in boisterous conditions.

If you. can go a few feet longer (temporary garage extension?) look in the WoodenBoat store at the 18' Swampscott 'John Dory'. My gunning dory was quite similar and proved a most capable sea boat suitable for open water or sneaking up a tickle.

This general class of dory is noted for very narrow bottom and very broad garboards with maybe 15-20 degrees of deadrise. Thus they can be a little twitchy if light and dead upright but gain huge stability as you try to depress one side or the other. With an oar for balance, I could walk my 200# along the gunnel. Sailed no fear in Fresh to Strong Breeze, Force 5-6, wind about 25 knots. Very few small boats are remotely safe or comfortable in such conditions.

Not the hottest sailer but quite lovely under sail or oar. Big enough to take your beloved and a dog, maybe even some beach camping and cruising.

The dory shape has the advantage of being easy to build with plywood and epoxy.

G'luck

[Rumars]

Your problem is the chosen lenght, there are very few keelboats in that range. A longer skinnier boat uses only little more material then a shorter wider one, so the sensible thing is to go longer. If you are not draft constrained it's easy to put the same amount of ballast lower and achieving the same righting moment with less mass. In order to still be able to easily trailer and launch you want some form of lifting keel, the simplest beeing a ballasted daggerboard. Nice to have features would be a self-bailing cockpit and positive flotation.

You haven't said what type of construction and look you want, if cold molded, strip or plywood, traditional or modern, so here some options:
https://www.benford.us/index.html?scp/ a 12ft keelboat originally designed for ferro, but able to be cold molded.
https://dixdesign.com/DS15.htm a ply round bilge dinghy with a ballast keel option

[Woxbox]

The best type of small boat for your local waters will be strongly suggested by the traditional boats used there. I'm thinking of the stoutly built double-ended fishing boats one sees around the Mediterranean.

[dbp1]

There are a handful of well-liked dinghies in that range that, if not anywhere as stable as a keel boat, at least are quite seaworthy in the right hands. e.g., Vivier's ILUR, Welford's Navigator, etc. There are also little water ballasted boats that, at the very least, are a lot more stable than the alternative (e.g., SCAMP).

[ahp]

Does it need to be traditional, or workboat inspired? If not there are any number of possibilities. Is plywood acceptable? On this side of the pond there is the Bluejay one design, a 14 ft LOA, V bottom center boarder with a conventional jib and mainsail rig. It has an excellent reputation. I have sailed one many times. On your side of the pond I have heard about the Mirror dingy, another plywood centerplate boat which was widely built I think, but maybe not so much now. One did voyage from England to the Black Sea. I suppose you know that.

[Peerie Maa]

Does it need to be traditional, or workboat inspired? If not there are any number of possibilities. Is plywood acceptable? On this side of the pond there is the Bluejay one design, a 14 ft LOA, V bottom center boarder with a conventional jib and mainsail rig. It has an excellent reputation. I have sailed one many times. On your side of the pond I have heard about the Mirror dingy, another plywood centerplate boat which was widely built I think, but maybe not so much now. One did voyage from England to the Black Sea. I suppose you know that.

Mirrors are good boats, but are one design boats built from kits. If it does not need to be traditional one of the Shetland inspired double enders would be a good way to go, or a design from the Woodenboat store.

https://www.woodenboatstore.com/coll...-pulling-plans
https://www.woodenboatstore.com/coll...aysailer-plans

[rbgarr]

Do you mean 'tides' as in rise and fall of them, or currents about fast water moving in and out of areas you'd want to sail in? A big rise and fall of tides may limit launching times and places unless the boat is moored in the water all the time. Rapid currents may determine how well you want the boat to sail and maneuver.

A small keel boat in the range you suggest could be LYNX, a 15' keel catboat with jib, self-draining cockpit and cabin drawn by Phil Bolger. It's on p.89 of his book "Small Boats".

[lupussonic]

The Med has a short choppy wave compared to the Altantic, mostly very tame in coastal waters and with absolutely no tide. The wind can of course blow ten bells however.

The winds are extremely flukey, can vary in strength and direction every ten minutes, particularly in coastal waters as the land gets so hot in the day it dominates what the wind is doing. I have sailed extensively in the Agean and Ionian, and I know that I would like a sail that I can drop in an instant or reef very quickly if I was thinking about which boat to take. Balanced lug with a jib and 30% mizzen would get me there.

If I were you I would go down to the nearest harbour and look for traditional designs. The builders have already done the evoluton of good safe craft suited to their native waters for you over 1000's of years.

[neil.henderson]

We lived for a while between Nice & Cannes - I remember the Mistral well!! Came from nowhere & blew a blast very quickly. So yes, I'd go for a design which will keep you dry & safe in windy/choppy weather.
A Gartside, Vivier or Oughtred design would likely suit, what about Iain Oughtreds Caledonia Yawl - a bit larger than you were thinking of perhaps, or Viviers Ilur.

Regards Neil

[ghostdog]

A lot of good information and advice has been given. To put it all together.

A generous freeboard, round bottom, deep keel, and ballast are the qualities to look for.

My restrictions are:
12'-14' length. 16' is the upper limit for tax reasons, but as we all know a smaller boat gets used more than a bigger one. Also at 16' it would be a lot harder to singlehand in and out of the water.
It has to be trailerable. Mooring space is rare and expensive. I have space in my yard to store it on a trailer and I live 20' drive from the sea. So keelboats are not an option. For the same reason I would prefer the use of movable or disposable ballast over permanent.

I totally agree with the advice that traditional working boats are perfectly adapted for the local conditions of any area. Plus they are very good looking. I doesn't have to be a double ender. In small sizes a transom means more internal space for a given length. There are traditional small boats with transom called "papadia" (Fun fact: papadia in greek means "priest's wife" ).

The descriptions you gave about the conditions of the Mediterranean are accurate. During July and August we have strong north winds that can start or stop unexpectedly within minutes. When the sea is calm, it is full of jet-skis and speedboats. There are also three months in the heart of winter that it is too cold and rainy. That leaves us with seven months of relatively good weather and no speedboats, perfect for sailing, paddling or whatever you like. Not bad at all.

Used sail boats do not exist here, because recreational sailing does not exist. Everyone has an outboard. Only sailboats available, are racing dinghies (optimists and lasers) and 30' cruising boats for rent to tourists. So it has to be homemade. Stitch and glue, for ease of construction or strip build, for good looking round bottom, would be preferred. Clinker ply would seem Northern European and out of place.

Of the available designs that fulfill the above criteria the Ilur from Vivier would be a good candidate, although at 300kg (almost 600 pounds at the other side of the world ) it is a little heavy.
The Morbic 12 from the same designer is nice but only clinker ply version. There is a strip version but it is 11'. Too small.
An other design that looks promising are the Stornoway 12' or 14' from Selway-Fisher. They look nice and they have options for strip build and many rigs to chose. I don't know how seaworthy they are but I think with a little more freeboard (if needed) and some movable ballast inside, one of them could fit.

[John hartmann]

I have not found the Ilur to be so heavy as to be cumbersome trailering, or launching/retrieving. For her weight, she rows very nicely. When I am single handing in fresh breezes and busier sea states I find that 20-40kg of lead shot in small satchels below the sole and along the CB trunk settles her nicely. It might be worth seeking out designs that use water ballast if you don’t want to deal with additional ballast, something like the slightly larger ebihen, which also has a motor well if you don’t fancy rowing. The Ilur is a boat that will take good care of you when things get sporty.

[John hartmann]

Vivier has a design for a water ballasted felluca inspired boat called the Gabian:

340E29DA-91E7-4559-8CE5-A988B4247917.jpg
039DE5DB-6307-4DA7-98D6-175FCFF1C873.jpg

[ghostdog]

Yes, I have seen the Gabian. It was one of my first considerations. Unfortunately as many other Vivier's nice designs it is available only as a kit. The cost of the kit will be twice the cost of local materials, not to mention the shipping cost.

Another similar design is Gartside's Gozzo. A replica of Italian fishing boats. The plans of it are for traditional plank construction and I am not willing to do it that way. I could use the lines and offsets to built it strip built but I prefer a complete plan where a naval architect has done the calculations.

As for the Ilur, I have not dismissed it yet. It is still under consideration given it's reputation.

[John hartmann]

I have sailed in company with the Calendar Islands 18. It is an impressively capable boat:
0477A0C9-BE2D-4B85-9E5D-6617B08A06FC.jpg

[Peerie Maa]

Another similar design is Gartside's Gozzo. A replica of Italian fishing boats. The plans of it are for traditional plank construction and I am not willing to do it that way. I could use the lines and offsets to built it strip built but I prefer a complete plan where a naval architect has done the calculations.

I am sure that if you contact Paul he will confirm that strip plank can be used.

[Clinton B Chase]

ghostdog,
There is a lot more built into a kit than just the materials - you shouldn't discount the kit as a possibility. Think about the huge time savings. If you love the Gabian, go for it. You could also consider talking with Vivier to see if plans could be drafted, but don't expect that to be high on his list. But then again you want 14' right?
You could also consider the Calendar Islands 16 and 18. A large dory might do the trick as well, Like an Alpha-Beachcomber. You would get shallow draft with ability to beach and good sea keeping qualities, with the aforementioned designs.

[John hartmann]

Acknowledging the hefty price increases of plywood in a post pandemic world, the time savings and precision of the CNC kits is a very considerable added value. Having built a number of boats for my own enjoyment, I’ve never considered the value of my own time, rightly or wrongly. The steeper entry costs of the CNC kits are offset by how well they facilitate a nice build quality, and the speed with which they get me on the water. Good luck in your decision making; home builders enjoy an embarrassment of riches when it comes to well sorted and proven designs these days, and you will no doubt find one that you love and which serves you well.

[Clinton B Chase]

One explanation regarding shallow vs deep water boat with regard to seakeeping ability has to do with the shape of the hull and how it interacts with the waves as the hull moves through the water or the waves move past the hull in the case of a following sea. In general a deeper hull section that is less wide a flat (we might say it has more 'deadrise') will have a slower motion or greater inertia (especially if it has some ballast) through the waves and waters, making it more comfortable and less "sporty" in gusty conditions. This same boat might actually have less initial stability than one might expect of such a "seaworthy" boat. A vessel that is shallow and flatter on the water, actually will have excellent initial stability - the number we look at is the 'GM' or metacentric height (technically actually a radius) - a shallow, wide, hard bilged hull form will have a greater GM than a deeper, narrower, slacker bilged hull form. A shallow, relatively wider hull form tends to have a "quick" motion in a seaway, sitting more on top of the water, and it really relies on the people inside to generate the stability so it is more work and less comfortable to sail.

[ghostdog]

One explanation regarding shallow vs deep water boat with regard to seakeeping ability has to do with the shape of the hull and how it interacts with the waves as the hull moves through the water or the waves move past the hull in the case of a following sea. In general a deeper hull section that is less wide a flat (we might say it has more 'deadrise') will have a slower motion or greater inertia (especially if it has some ballast) through the waves and waters, making it more comfortable and less "sporty" in gusty conditions. This same boat might actually have less initial stability than one might expect of such a "seaworthy" boat. A vessel that is shallow and flatter on the water, actually will have excellent initial stability - the number we look at is the 'GM' or metacentric height (technically actually a radius) - a shallow, wide, hard bilged hull form will have a greater GM than a deeper, narrower, slacker bilged hull form. A shallow, relatively wider hull form tends to have a "quick" motion in a seaway, sitting more on top of the water, and it really relies on the people inside to generate the stability so it is more work and less comfortable to sail.

Thank you for the excellent explanation. It makes sense now.

I can relate it to kayaking and the way a Greenland kayak with low initial stability can easily go in rough sea, while a stable flat bottom sit on top has a hard time in waves.

[Edward Pearson]

This will feed the dream while you finish the canoes.



Duxbury had a good time in his plywood Drascombe. Its a couple of years since I read it (copies are available for £5-10. I remember he anchored off the beaches and on one occasion got caught by a passing tanker wake putting up quite a shore break as it shelved. I think he also had the odd occasion where katabatibc winds and wind curving around islands and around cliff faces, left him once or twice in a precarious state. His outboard saved his boat on at least one occasion. Fully laden, he had to winch her out on rollers using a tree when he wanted to scrub her off. I think once he had a swarm of angry bees in the boat. I got the impression he'd have like a small cabin by the time he finished. All the sailing was done by mid day before the meltemi blew up. I went to Bodrum once and the coast and islands of the Aegean must be one of the best places to small boat cruise on Earth, but the water conditions mid afternoon were not one I'd have chosen to be out in...in any boat, better things to be doing.

That Gozo boat is in a past Watercraft magazine and was shown for glued construction, two or three layer cold molded. He'd do a construction drawing for strip I'm sure. There was the beginnings of a traditional sail and oar festival in Greece last year.

Ken wrote a series, he drove down, launched I think on the mainland, cruised the Aegean with his wife and the sailed it back to England along the Med then up the French canals...

Here's a copy for £3.50

https://www.wob.com/en-gb/books/ken-...E#GOR003987790

[WI-Tom]

Here is the entire 3-book series on Ken Duxbury's LUGWORM adventures, from Lodestar Books:

https://lodestarbooks.com/product/th...rm-chronicles/

14 GBP for 3 books. Lovely edition--I had one myself.

Tom

[Jack Loudon]

John Welsford has a couple of boats that I think meet your criteria. Houdini is just over 13 ft long with wide 5'10" beam. Truant is smaller at 11'6" by 5'4".

JW has this to say about Truant, but should apply also to Houdini: "She is so designed that she will be comfortable to sail, dry in most weather, capable beyond almost anything else of her size and almost impossible to capsize. Her wide beam and smallish centreboard cause her to slide off sideways rather than tip out, her generous freeboard and wide decks help keep the water outside where it belongs and she has so much enclosed locker and air tank space inside that should the unimaginable happen there is enough buoyancy to float her crew completely clear of the water when fully swamped."


https://duckworks.com/houdini-plans/