Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rating: Thread Rating: 6 votes, 5.00 average. Display Modes
Old 29-11-2010, 15:39   #16
Registered User
 
Cormorant's Avatar

Join Date: Jan 2009
Location: Catskill Mountains when not cruising
Boat: 31' homebuilt Michalak-designed Cormorant "Sea Fever"
Posts: 2,073
There's a very good Bolger Yahoo Group. You might want to try posing your question there.

The first Bolger design that leaps to mind is his Yonder. 30 feet long, 10 foot beam, mast in a tabernacle.

http://www.hallman.org/bolger/yonder.gif

A bit bigger than you mentioned. I don't think it will beach flat, but you could add beaching legs. It was built for Alaskan seas, and could do a circumnavigation if you wanted.
Attached Thumbnails
Click image for larger version

Name:	Yonder.jpg
Views:	435
Size:	160.4 KB
ID:	21561  
__________________

__________________
Cormorant is offline   Reply With Quote
Old 29-11-2010, 16:16   #17
Scurvy Dog
 
Skylark's Avatar

Join Date: Feb 2003
Location: Lake Michigan
Posts: 121
One top requirement for an offshore monohull is that it be self righting. Some ways to ensure this with a shallow draft boat:

Put a lot of rocker into the the hull
Internal ballast in the lowest point of the hull
Make the topsides curved like a barrel so it is unstable upside down
Add a cabin house that is lightweight and adds flotation up high, which makes the boat unstable when it is upside down
Keep the deck smooth with few items that would slow a roll when upside down
Have vents that close and do not allow air entry when upside down

Those are a few ideas, but a multihull or a bilge keel boat is the easier way to do it.
__________________

__________________
+ - - - - - - - - - - - - - - - -
Skylark
http://cruisenews.net
Skylark is offline   Reply With Quote
Old 29-11-2010, 17:33   #18
Armchair Bucketeer
 
David_Old_Jersey's Avatar

Join Date: Oct 2006
Posts: 10,013
Images: 4
Have a look at a Fairey Atalanta. or the smaller Fairey Fulmar.

Fairey Atalanta - A 'Proper' Boat ( & Cheap ! )

Atalanta



Wood of course, but hot moulded veeners - so no leaky planking Floats in a saucer, with drop keels. Have crossed the Atlantic.
__________________
David_Old_Jersey is offline   Reply With Quote
Old 29-11-2010, 21:33   #19
Registered User
 
Thames's Avatar

Join Date: Nov 2010
Location: Thames Valley, England
Boat: bicycle
Posts: 46
Arrow

Thank you for all the replies. I'd have replied earlier but on hitting 'Submit Reply' I got the error message: "We have marked much of your activity as suspicious, you cannot perform this function at this time." Weird or what...?

I had thought a multihull was out of the question because the maximum beam that can reach the Thames at Oxford is 14'. But the Hirondelle catamaran mentioned above has a beam of only 10' - what's the average beam for a sea-worthy cat than can accommodate one man comfortably? The thing that scares me about cats is that when they capsize (1000 miles from land), aren't they impossible to right? Not sea-worthy in my books.

I appreciate that exploring creeks and rivers and crossing an ocean are ventures for two entirely different boats. I don't intend to cross an ocean any time soon... I currently sail dinghies on the Thames in central London and when I get my boat I'll be just nosing out of the estuary very cautiously, eventually breaking across to France and back on a fine day.

Perhaps my first boat doesn't need to be ocean-worthy, the next one can be a few years down the line. But even then, after crossing the oceans the ability to sail my home right back up the Thames to see my folks and to rest afloat would be fantastic. The Thames at Port Meadow, Oxford:


I agree I could probably get a GRP bilge keeler that'd do the job for a couple of grand and this would work out much cheaper initially. I appreciate that people study for years to be able to design a boat, but it's the designing, not the building that intrigues me, although I enjoy working with my hands. I want to be able to do my own maintenance and am put off the idea of a boat that someone else designed and built that I don't understand, pull one part away to repair and discover more problems underneath! Break a spar or component and discover that the replacement costs £800!
__________________
Thames is offline   Reply With Quote
Old 29-11-2010, 21:48   #20
CF Adviser
 
Bash's Avatar

Cruisers Forum Supporter

Join Date: Dec 2008
Location: sausalito
Boat: 14 meter sloop
Posts: 7,260
Quote:
Originally Posted by Thames View Post
I also want the boat to be sea-worthy enough to cross the North Sea.
I've crossed the North Sea. Trust me, you don't want to do it in anything that could each Oxford.
__________________
cruising is entirely about showing up--in boat shoes.
Bash is offline   Reply With Quote
Old 29-11-2010, 23:15   #21
Registered User
 
aquarian's Avatar

Join Date: Sep 2010
Boat: Vagabond 42
Posts: 269
Quote:
Originally Posted by Weyalan View Post
To be blunt, you don't design a boat. Thats what Naval Architects do, and they spend years, if not decades, learning their craft.

You have, I think, 2 possible solutions:

1. Buy 2 boats - one for puttering about on the Thames and 1 for blue-water offshore sailing

2. Buy a shallow draft multihull - it will be a bit of a compromise for both of your stated goals, but will probably do the job.

So, where do the Naval Architects come from? Bet they had dreams too.
__________________
P-)
aquarian is offline   Reply With Quote
Old 30-11-2010, 03:42   #22
Freelance Delivery Skipper..
 
boatman61's Avatar

Community Sponsor
Cruisers Forum Supporter

Join Date: Jan 2010
Location: PORTUGAL
Posts: 20,225
Images: 2
pirate

If design is your aim and you want to do it to the spec's you stated... and keep it simple I'll restate... get the Maurice Griffiths plans on CD for the Senior (19ft) and the Eventide (26ft)... the detail will give you a lot of info on structural strengths.. distances for frames, techniques etc.. the plans cover long/bilge and centre plates and at 13quid for the pair will set you well on the road... they are hard chined and very well proven sea boats that have cruised the Med and Caribbean.. well the Eventide certainly has... as has the Waterwitch and Wild Goose...
__________________


Born To Be Wild
boatman61 is online now   Reply With Quote
Old 30-11-2010, 07:22   #23
Senior Cruiser
 
nautical62's Avatar

Cruisers Forum Supporter

Join Date: Jul 2008
Location: Live Iowa - Sail mostly Bahamas
Boat: Beneteau 32.5
Posts: 2,264
Images: 12
If you want some production boat examples for ideas you might look to the Westerly Centaur (26) or Westerly Pageant (23) - two very well built english boats sporting drafts of 3 feet or less. Both are bilge keels. Picking one up used may be much cheaper than building something.

The Heavenly Twins Catamaran is 26 feet and has an advertised draft of 2'3"
__________________
nautical62 is offline   Reply With Quote
Old 30-11-2010, 07:33   #24
Freelance Delivery Skipper..
 
boatman61's Avatar

Community Sponsor
Cruisers Forum Supporter

Join Date: Jan 2010
Location: PORTUGAL
Posts: 20,225
Images: 2
pirate

Quote:
Originally Posted by nautical62 View Post
If you want some production boat examples for ideas you might look to the Westerly Centaur (26) or Westerly Pageant (23) - two very well built english boats sporting drafts of 3 feet or less. Both are bilge keels. Picking one up used may be much cheaper than building something.

The Heavenly Twins Catamaran is 26 feet and has an advertised draft of 2'3"
I think Catamarans are out for the OP as to get to Oxford he has to pass through quite a few locks which are pretty narrow... thats why the English canal barges are in the main only 6ft beam... its not to bad lower down the Thames but further up could be a problem... more than 10 - 12 ft is a no no...
__________________


Born To Be Wild
boatman61 is online now   Reply With Quote
Old 30-11-2010, 08:49   #25
Senior Cruiser

Cruisers Forum Supporter

Join Date: Mar 2006
Posts: 1,594
IF you can really live with 3.5' draft,, just buy a Cape Dory 25D and add a mast tabernacle
__________________
Randy

Cape Dory 25D Seraph
rtbates is offline   Reply With Quote
Old 30-11-2010, 09:39   #26
Registered User
 
Thames's Avatar

Join Date: Nov 2010
Location: Thames Valley, England
Boat: bicycle
Posts: 46
A Cape Dory 25D appears to be fin-keeled and would fall over when beached as the tide goes out.

Bilge keelers are of interest. I've seen some secondhand that look ok for less than £3000 (although GRP ). I've inquired about the Eventide plans, although one sentence in the description worries me: "well able to face conditions offshore, to the extent of being able to right if ever knocked down." I always thought any boat going offshore must not only right itself when knocked down, but right itself even when upside-down! Although it's encouraging to hear that they've cruised the Med and Caribbean. An Eventide:


What is the average draft for a sea-going bilge keeler? And has anyone crossed an ocean in one?
__________________
Thames is offline   Reply With Quote
Old 30-11-2010, 10:00   #27
Freelance Delivery Skipper..
 
boatman61's Avatar

Community Sponsor
Cruisers Forum Supporter

Join Date: Jan 2010
Location: PORTUGAL
Posts: 20,225
Images: 2
pirate

Quote:
Originally Posted by Thames View Post
What is the average draft for a sea-going bilge keeler? And has anyone crossed an ocean in one?

The Eventide should right herself ok if rolled... the ballast if I remember rightly is built into the long central keel and any extra ballast to balance the boat out after launch should be packed into place and kept there with a plate of wood or metal to stop it falling out in the unlikely event of a roll... the bilge plates are purely so the boat can dry out without falling over... vital in the UK tidal waters.
Another factor is... and I may be wrong... but its my opinion hard chine does not roll as easily as round hulls... one reason hard chines are so favoured by the French designers... excluding Beneteau.
Furthermore draught IMO does not affect stability as many seem to think.... else the majority of boats would be 6ft plus draught.... a 331 (34ft) is only 4.5ft
The only thing you lose out on with bilge is ability to point as high as a single keel but the economical benefit of being able to freestand makes pointing an irrelevance... just be sensible and don't get caught on lee shores
__________________


Born To Be Wild
boatman61 is online now   Reply With Quote
Old 30-11-2010, 10:08   #28
cruiser

Join Date: Nov 2008
Posts: 506
A yacht designer?
A naval architect?
A guy who at 14 years old aranged his bedroom to look liike a yacht design office then spent the next 50 years, 50 years, trying to learn the art/science of yacht design?

What value could that guy have to offer?
__________________
bob perry is offline   Reply With Quote
Old 30-11-2010, 10:12   #29
Freelance Delivery Skipper..
 
boatman61's Avatar

Community Sponsor
Cruisers Forum Supporter

Join Date: Jan 2010
Location: PORTUGAL
Posts: 20,225
Images: 2
pirate

Quote:
Originally Posted by bob perry View Post
A yacht designer?
A naval architect?
A guy who at 14 years old aranged his bedroom to look liike a yacht design office then spent the next 50 years, 50 years, trying to learn the art/science of yacht design?

What value could that guy have to offer?
Bob... is that you.... or Maurice Griffiths....
__________________


Born To Be Wild
boatman61 is online now   Reply With Quote
Old 30-11-2010, 10:17   #30
Registered User
 
limejucer's Avatar

Join Date: Sep 2010
Location: UK,Bristol
Boat: Prout Snowgoose Elite
Posts: 142
D'ont wory about cats capsizing. it is the trade against sinking. I recomended Annes book which offers designs for dory monohulls(and philosophy). But my new boat is an ocean going cat. they are all compromise between cost performance and comfort. a ball shaped boat would give max volume exelent recovery from capsize but mimimal speed. long thin boats are fast but less stable until heavy keels weigh them down.

So a simple bilge keeler like shrimpy would do it as would a small Cat. the important limit is the crew and skippers skill

PS here are shrimpy's details from Wikipedia
Shane Acton was a sailor, known for circumnavigating the globe in an 18-foot (5.5 m) boat. He first set sail from Britain at the age of 25, in 1972.
Raised in Cambridge, England without any sailing experience he departed in a used 18' 4" bilge-keel sailing boat for which he paid £400 - not an enormous amount even in the early 1970s. The boat was a 'Caprice', a Robert Tucker design originally named 'Super Shrimp' but referred to by Shane simply as 'Shrimpy'. Later Shane was accompanied for much of the voyage by his girlfriend, a photographer from Switzerland, Iris Derungs, he sailed westabout through the Panama Canal, circling the globe and returning back to England as a local celebrity eight years later.
__________________

__________________
limejucer is offline   Reply With Quote
Reply

Tags
draft, seaworthy

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Boat brands that are not seaworthy? wannabesailing Monohull Sailboats 97 26-10-2015 19:59
Challenge: Getting a Boat with a 5.5' Draft Through a 5' Channel b-rad Challenges 27 18-10-2010 10:32
Shallow Draft Boat for Sale in SE Asia ? Gone2long Pacific & South China Sea 0 26-09-2010 08:13
Valiant 40 Shoal Draft vs Full Draft CaptainBW Monohull Sailboats 7 11-08-2010 16:06
powersailer, diving boat, trailersailer, fishing boat, sailboat, powerboat, 12"draft BernieOdin820owner Fishing, Recreation & Fun 1 04-12-2007 18:56



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 04:26.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.