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skaraborgcraft
08-12-2010, 04:01 AM
Hi all,

I have another thread running about Atkins Two Brothers design and its expected performanve on 12hp. What we are looking for is an easily driven hull with the following requirements.

Boat will be kept on a summer mooring that is behind a rock shoal that has just over 2 ft clearence, the present boat has been bashed and scraped over these (mostly) smooth rock for most of its life, and its draught is less than it used to be! Boat will need to be trailered and so weight and beam is restricted. Boat will be used on the west and north coast of Norway, most of the coast has "inside" passages,but some of it is open,and it can get nasty...
owner can wait out these rough weather fronts onboard and so needs a comfortable living space for two,with cooking and elbow room.....he also has small grandchildren for short periods, so 4 berths are needed. Engine must be diesal. Steadying sail or small rig. Owner is used to having a wheelhouse but understands he may not get it in this package,and will accept canvas sprayhood and dodgers or open back shelter. It must be wood, clinker, ply lapstrake , strip plank or cold moulded. Owner would prefer real wood clinker, but realises that a ply lapstrake boat will be dry and better suited to trailer journeys. The owner does not have a bottomless pocket, and so simple design and fast build would be preferable,but low operating costs are the primary target. This guy has the experience to look after the boat,and not the other way round.


So.....

Maximum length 29ft / 9m

Maximum beam 8ft 4 in / 2.5 m

Maximum weight 3 ton / 3000kg

Maximum draught 2ft / 60cm

An engine max of 16 hp and preferably less

A sustained speed of 8 knots

Boat must have a full keel or protected propellor

berths for maximum of 4

steadying sail or small rig

If you can check out the design of Two Brothers,you may see why this so far seems to be the most practicle and fit for purpose so far found. Appriciate any comments. Cheers

erster
08-12-2010, 07:42 AM
The issue is the draft that an inboard requires coupled with enough bottom for open seaway conditions and still sticking with a maximum overall of two feet. Creating a boat that sleeps four is not really an issue in LOA of 29' with the requirment of it being diesel. But you go back to the draft of two feet and you have eliminated a lot in regards to operating in open water. Even with a skeg to protect the running gear, the lack of bottom is not in your favor when you take the boat offshore.


To get decent interior space you must go up. You really have a reserve of only about eight inches tops to play with for a boat and a decent engine hp to push the boat safely offshore operating as a power boat that will do a decent job offshore or even along any coast in open water. We normally figure 16 inches to start with for enough room to fit the running gear wheel included on any recognized angle from the bottom of any configuation.
Figure that from a draft of even 8 inches for the shallow of all draft which is not much of an offshore boat and you have reached your requested draft right there.

You are really back to a shallow draft sailboat design with limited amount of room inside for any real practical accomadations. With a semi displacement trawler design you can tuck your gear up a bit but also restrict the flow of water to the running portion too if you go too much in a shallow draft boat. This creates some overall handling issues too if you primarily want a motor boat.

keyhavenpotterer
08-12-2010, 10:45 AM
You need a good sharpie.

Ian Oughtred Haiku. Draws 1ft only. This gives plenty of reserve if your over the rocks in a wave trough. Beautiful and elegant. Sleeps 4. Quick and economical to build. 30ft.

http://www.nisboats.com/oughtred/sharpies.html

Also look at Norwalk Island Sharpies. The NIS range say 26ft would be big enough for 4. and has a 10 inch draft. Proven very large angle of vanishing stability in case of offshore use. Proven fast too in races and proven offshore capabable in adverse conditions. Designed by Bruce Kirby of Laser fame.

http://www.nisboats.com/mainpages/nis26.html

Mark Van
08-12-2010, 11:48 AM
Didn't Atkin designed a larger version of the Rescue Minor with a cabin? It seems like that hull shape would be ideal.

JimConlin
08-12-2010, 12:41 PM
Didn't Atkin designed a larger version of the Rescue Minor with a cabin? It seems like that hull shape would be ideal.

Alex Hadden built an Atkin tunnel hull . The boat was named Noble Cab.

Covey Island built a Dave Gerr design named Summer Kyle.

Both boats have gotten a lot of ink.

skaraborgcraft
08-12-2010, 01:16 PM
Neither i or the owner have an issue about 2 feet draught being able in big seas, though i agree a deeper draught will allow much accomodation.

Keyhaven..... I did mention sharpie, but that bought a large intake of breath through the teeth......This is mostly motor boat i should point out,the sails are purely for roll damping or sail assist, this guy really does not want to be pulling strings and cruising at an angle ....in which case the sharpie would slam too much cruising upright.

Atkin did a larger tunnel type skiff at 28ft called Nanuk 111 , its too beamy at 9ft and requires 35hp for 12mph.......we are looking for more efficient motoring than that.

Thanks for the suggestions so far...... TB is still front runner.

jrobbins
08-12-2010, 01:38 PM
Just read the article about the Rescue Minor , very interesting design, has anyone ever built that hull designs for smaller rivers like we have here in south georgia

keyhavenpotterer
08-13-2010, 02:41 AM
Have you looked at Paul Gartsides Motor Cruisers.

http://www.gartsideboats.com/cat.php#motorsail

He has a a very nice 24ft shallow draft motor-cruiser called Wayward. It has a narrow beam for canals/ inland waterways and an inboard 'outboard' arrangement, making a very efficient cruiser both to build, service and use. Paul has many other nice boats for sail or motor too.

http://www.gartsideboats.com/wayward.php

Ian Oughtred has also penned a 23ft motor sailer design. Not in his published catalogue but he has it. There is one for sale here to look at one, if he likes Ian Oughtred designs.

http://westscotland.boatshed.com/oughtred_motor_sailer_23-boat-106724.html

Lyme Regis boatbuilding Academy built a very nice Petterson coastal motorcruiser last winter.

http://www.boatbuildingacademy.com/students/studentprofilesmarch09/petterssonmotorboat.htm

skaraborgcraft
08-13-2010, 02:54 AM
Keyhaven....thanks for the links. Wayward is a nice concept,but in this instance not suitable,a 25hp outboard is twice the power we are looking to use and the wrong fuel,though its a very nice hull and worthy of future consideration.

That Pettersson runabout is a gem!

Cheers

keyhavenpotterer
08-13-2010, 03:36 AM
There was an article in a recent Watercraft about 'Lola' the Petterson design. It was a looker. Lars who built her said she was really good in the swell of Lyme Regis. he had a small inboard diesel. I think he said it was only 10hp. It made a fine noise through the exhaust (like a V8) and made her semi plane at a good speed.
http://lh5.ggpht.com/_fbcfUhcwruA/Sx0KSlshq_I/AAAAAAAADVw/Hmgbu2Ahhk4/s800/Lyme%20Regis%20Boat%20Building%20Academy%20launch% 20Dec%205th%202009%20021.jpg
http://lh5.ggpht.com/_fbcfUhcwruA/Sx0LVzzglqI/AAAAAAAADVs/E_2sVqq3lPQ/s800/Lyme%20Regis%20Boat%20Building%20Academy%20launch% 20Dec%205th%202009%20072.jpg
http://lh5.ggpht.com/_fbcfUhcwruA/Sx0LbW26D5I/AAAAAAAAAGY/XymbnezroVM/s800/Lyme%20Regis%20Boat%20Building%20Academy%20launch% 20Dec%205th%202009%20076.jpg
http://lh6.ggpht.com/_fbcfUhcwruA/Sx0LQjb-9OI/AAAAAAAAAF8/A-Ub8DXwYrg/s800/Lyme%20Regis%20Boat%20Building%20Academy%20launch% 20Dec%205th%202009%20069.jpg
I took some photos on the launch day if your interested in her. Scroll through to see Lola...

http://picasaweb.google.co.uk/milfordvet/LymeRegisBoatBuildingAcademyLaunchDec5th2009#

keyhavenpotterer
08-13-2010, 04:50 AM
Just found C. G. Pettersson's website/ association/ library of many photo's and a design list:

http://www.trabatsakuten.nu/cgpsida/Pettersson_English.htm

http://www.nykroppa.se/nbk/ritningar/index_2.htm

Many to choose from, but I think she's this one:-

http://www.nykroppa.se/nbk/ritningar/motorbatsbyran/28.jpg

This ones like Lola but with a tapered stern. Very nice....

http://www.nykroppa.se/nbk/ritningar/motorbatsbyran/29.jpg

There are others with more protected props if thats essesntial.

perldog007
08-13-2010, 05:56 AM
St. Pierre Dory

Egret from the WoodenBoat plans or Parker's version for more modern construction. ( 28' double ended sharpie )

JimD
08-13-2010, 06:32 AM
I got the impression you are looking for something more like Martha Green, that is to say a shallow draft power boat with sail assist, although with a little less draft (MG draws almost three feet):

http://www.boat-links.com/Atkinco/Cruisers/images/MarthaGreen-5.gif

skaraborgcraft
08-13-2010, 12:14 PM
something like Martha green,but bigger, but needs to perform 8 knots with minimal HP 16 hp max.

Keyhaven......thanks for the links,im in Sweden so Petterssons are about as common as a slipper launch in the UK. They are very able boats and very fuel efficient designs. Lola looked as though she was fitted with what may have been a saffle or skandia engine, very low rpm, buetifull sound,economical and last a lifetime. Cheers