Bluejacket, how long?

I reread Tom Lathrop's articles in Boatbuilder on Bluejacket (Liz).
The more I studied the more I liked it. So the question is. How long can that hull be while keeping a beam of less than 8' 6"? That is the widest you can be on a US highway without a permit. I'd like to see 6' more of cabin and keep the aft deck. At 30' it would still be under 5000 lbs. It wouldn't be fun to pull on a trailer but you could do it. I use to pull a 32' foot camper around.

Tom have you done any more model work with longer hulls?

It's a wonder I ever get any sleep with all this spinning around in my head.

 

Guest? That was me. I have to remember to log in.
Gary

 

log in..

Got your......cookies turned off?

 

Sorry Duluth, I missed this thread. I have thought about a somewhat larger boat but have not done any serious work on one. It could possibly be a viable option for the high speed coastal cruiser design project. The present pilothouse is about seven feet long (84 1/2"). Six more feet and another 6 inches width would be quite a large cabin. I suppose you are thinking about another two guest bunks in a table space.

 

Adding the extra berths would be a plus. My reason for the larger cabin is that where I would use this boat the water temp. rarely reaches into the 50's F. Small cabins make me cranky. But I would still like to have an aft deck. I think 28' would be the minimum.
I started this thread because I was thinking about Bluejacket, and how long it could be streached. Would this improve or detracked from the handling.
This might not belong here, but I wanted to keep it separate from the design project.
Gary

 

Tom, I'm thinking of something like Devlin's "Black Crown 29". That boat has a 10' beam. I want to be 8.5' or less and use one or two outboards.
Gary

 

Gary,

I wrote the following without having seen you last post. Sam Devlins Black Crown or, more to my taste, his Topknot are very nice and well thought out boats. They are however, out of my price range and since they are rather high displacement boats, require a lot of power to make the desired speed and are not trailerable in any practical way.

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Gary,

I think that the Bluejacket concept could be lengthened to the size you wish. There are some things that should be looked at before such a leap is taken though. All too often someone wants a boat and looks around for something that strikes their fancy. When they find a boat that appeals to them (for whatever reason) they then start to consider changes that would make the boat more suitable for their needs or wishes. I think that is the wrong way to go about a design. If the changes or modifications are superficial or don’t affect the basic parameters of the design, then it is probably ok. If the changes are toward major revision of the size in length, beam, speed range or displacement, then a fresh look at the new parameters is the better approach.

Without reference to the boat that appeals to you, make a list of all the things that you want in the boat. Don’t agonize over the list, just jot down anything that you think you will like. Now go through the list more carefully and sort out those parameters that are incompatible with each other and make the choice of which of the incompatible factors are most desirable, throwing the other out in each case. Along the way some new features will be added and some old ones discarded for various reasons. This will take some time and study. A hot tub on a lightweight boat, is an extreme example of incompatibilities. Over time, the real and practical parameters of the new boat will take shape.

After completing this exercise, you may find that the boat that inspired you no longer looks so good or that it’s basic concept is incompatible with your list of “sacred goals”. On the other hand, it may fit very well or may, with some reasonable modifications here and there, suit your list just fine.

I am an amateur boat designer but as an engineer before I retired, I used this approach to design a wide variety of apparatus and systems. It is a well used and successful approach to new designs and often prevents the generation of botched designs with a lot of elements that just don’t fit together. It is the method I used to design the Bluejacket 24. I started with a little 17-foot convertible outboard cruiser by Weston Farmer that I first saw in an issue of “Science and Mechanics” in the fifties. Although “Liz” is far removed in every major parameter from Weston’s “Sundance” that was the inspiration for her design, the family resemblance is clearly obvious.

I realize that this explanation has been a bit long, but I lack the time to make it shorter. I’ve forgotten where that quote came from but it is appropriate.

 

It's interesting how things develop, isn't it. My inital thoughts, when I posted my ULDB thread ( http://boatdesign.net/forums/showthread.php?s=&postid=1066#post1066 ) , was to come up with something exactly like you are talking about. I've done quite a bit of trailering with a large-ish boat ( my 27ft Searay) - moving the boat up and down the East coast of Australia. Behind the right vehicle, big boat towing is no great drama, so as long the boat is designed from the outset to be both light and trailerable, I see no reason why it couldn't be a great success. And the cases for keeping a boat out of the water are many and strong.
Bring it on I say!

 

I own a 28 ft Bayliner. It is the Cierra Sunbridge model. It is currently on a tripple axel trailer. It has a beam of 10 ft. I still tow it. I also have a Ford F-20 Superduty truck to tow it with. I have it in the yard for cost of storeage and to work on it. It weighs about 7500 lbs with about half tank of gas and no water onboard. The max width for the city streets is 8 ft. The highway is 10 ft. Neal

 

1st up - welcome to the forums Mitch.
This thread kind of evolved into the "Option One" project. You might want to check it out - and you'd be more than welcome to join the fun - the more the merrier......

 

Larger Trailerable Boats

You guys must be fresh water boaters. Light weight is good for making a boat efficient, but to be safe and especially comfortable in heavy seas, it needs a higher displacement to waterplane area ratio.

As Will and Mitch indicated, towing a large/heavy boat isn't too bad if the tow vehicle is adequate. My boat, "Portager," will be 36' long with a 10' beam and 19,000 lbs fully loaded. I'll use a Freightliner FL-60 or the new M2 class to tow it and I'll need an oversized load permit, but what's wrong with that? In California, I can get an annual oversized load permit for $92.

Mitch, I think you better double check your load requirements. My Motor Carriers' Road Atlas indicates the maximum legal width in Virginia is 102".

Cheers;
Mike Schooley