Utility Semi-Vee Hull

I am interested in designing a semi-vee hull or v hull boat for fishing and having fun on the river. I grew up fishing and messing around in boats similar to this 2021 Aluminum Deep V Utility V1460 Boats | Lowe Boats https://www.loweboats.com/utility-boats/v1460/. My intent is to design a 14-16 ft long boat to take a 15-25 hp motor that I can build with my son when he is old enough. I am thinking it will be a plywood design with fiberglass tape seams. I have some experience with building and repairing both plywood and fiberglass boats. I am a practicing naval architect so I am capable of the various calculations. However most all of my experience is with ships rather than boats of this size. Are there any rules of thumb / pitfalls I should be aware of for the design of a small semi-vee or vee hull outboard? Any guidance on location of max section or preferred deadrise ranges forward and aft etc? I would greatly appreciate any guidance. Also does anyone have a curve for estimating structural weight versus size for plywood boats of this size to help in the first iteration of the preliminary design?

I would also like to do some more homework looking at similar vessels. I know Bolger's Diablo is a design of this type as is Edwin Monk's Fisherman. The San Juan Dory in the plans Wooden Boat Magazine sells also looks to be in the same general type although the bow seems too fine to my eye. What other designs should I consider as potential sources of inspiration?

Thanks in advance.

 

Welcome to the Forum James.

Phil Bolger's Diablo certainly does seem to be a very fine design -
https://www.amazon.com/Build-Instant-Boats-Harold-Payson/dp/1934982040/ref=sr_1_1

If you do not yet have a copy of the above book, it would be well worthwhile getting one from Amazon.
And you could then use the plans within as a basis for drawing up your own design?

Another good source of small boat designs is Jeff Spira -
Spira Boats - Wood Boat Plans, Wooden Boat Plans https://spirainternational.com/hp_wood_boats.html

Re Ed Monk's Fisherman Skiff, is this the one that you are thinking of?
Ed Monk Skiff - Small Boats Magazine https://smallboatsmonthly.com/article/an-edwin-monk-skiff/

 

Thanks for your kind words and suggestions. I do have Payson's book. I also have Monk's "How to Build Wooden Boats" which has the design I referenced. It has a similar deck layout to the design you point to but it is vee bottomed and a little longer. Other books on my shelf include Gardner's "Building Classic Small Craft" and Bolger's "Boats with an open mind" but neither of them seem to have another design to consider for inspiration. Otherwise my collection for small boat design is heavily skewed to sailboat design which isnt much help on my current project. I seem to have misplaced my copy of Gerr's "Elements of Boat Strength" but it will turn up.

I did come across a few weight estimating rules of thumb for a first level estimate in Jim Michalak's writings Jim Michalak's Boat Designs/The Index http://www.jimsboats.com/1sep20.htm. They will get me started for first cut and once I get some detail in the design I can work up a detailed estimate piece by piece. But I am still open to any other data anyone is willing to share.

 

I really think the vee-bottom punt style of boat has advantages, in waters where it won't get too choppy, with a more rectangular plan you get more space for length, and good stability.

 

This type of thing, a "vee nose, vee bottom" punt, very little vee aft, just enough to bank into turns.

 

Sam Devlin has some designs which may be of interest. Devlin Designing Boat Builders https://devlinboat.com/

Deadrise is a fundamental design decision. Lower deadrise, particularly aft, generally results in higher speed and greater static stability. Higher deadrise, particularly aft, generally results in reduced slamming impact but reduced static stability. (Stability also depends on numerous other factors including displacement.)

I wouldn't worry too much about weight of the hull. Take the total surface area, multiply by weight of the plywood per unit area, and add a factor of 25% to 50% or so to account for frames, thwarts, floatation compartments, etc. Operating weight will probably vary by more than the bare hull weight due to number and weight of passengers, gear carried, etc.