As the sun dipped towards the horizon, Jeff Lord and I sat around the patio table, discussing his new boat concept. Producing a hand drawn sketch on a carefully folded sheet of paper, he asked "Could we design a boat to suit this drawing?" With our coffee's in hand and looking over his roughly drawn sketch, we discussed and drew slight variations of the boat, all the time keeping in mind it's purpose and nature. Overall, the idea looked like an interesting concept, and would be a real challenge to design in plywood. So in the end, we agreed upon a concept and proposal to design.
Overview
The Mangrove Jack 3.65 "V" nose punt is designed to be a compact "V" nose punt. Designed as a fishing vessel suited to sheltered and semi-sheltered waters, the Mangrove Jack 3.65 offers a great opportunity for those weekend fishing adventures, designed to be tough, reliable and seaworthy for those who love to venture out on the water.
The plans are large scale drawings printed on 2 ft by 3 ft sheets (or D size). The CAD plans are drawn to a very high degree of accuracy in both metric and imperial measurements. Included also is a building manual and material list.
Boat Specifications
Length of Hull: 12ft (3.65m)
Beam: 4ft - 9in (1.44m)
Depth: 2ft - 3in (.685m)
Freeboard : 1ft- 4in (.405m)
Transom Shaft Length: S/S (15" or 381mm)
Weight (boat only): 143 lbs (65kg)
Min Rec. HP: 10 hp
Rec. KW: 7.5 Kw
Max. HP: 15 hp
Max. KW: 11.2 Kw
Max. Main Motor Weight: 143 lbs (56kg)
Number of People (Basic): 3 (NOTE: 1 person = 1 adult or 2 children)
Max Load (Basic): 712 lbs (323 kg)
Design Brief
Jeffs Brief:
"Having been around boats of one sort or another nearly all my life, having built 2 and modified another, I currently own an aluminium
RANGER 3300 punt , which I am sorry I ever bought. I was after a lightweight plywood/composite boat, but after months of searching, I could not find what I wanted that would suit my needs.
Above: The initial hand drawn sketch that Jeff drew of the Mangrove Jack
What I was looking for was "V" nose tunnel hull punt, (a composite/ plywood design), with large "V" chines to provide extra stability when fishing and also for the boat to sit level when beached. I had been toying with the idea of building a V Nose punt of my own design, but how do you know if the design will work, let alone can it be built?
It also had to be lightweight for its size, with a high freeboard, quick and easy in it's construction and easily handled by 2 people. Is this possible? I asked Mark "
Jeffs later comments about the design:
"When I saw Mark's web site and spoke to him, I met a kindered spirit, and I asked him "Could he design the boat for me?". Well, I love what they've done! The interest shown in the design is great and it shows that Mark can turn a ham fisted amatuer designers sketch into a beautiful and sea worthy boat. I have printed off the drawing to show to the TREASURER. We think it looks excellent."
Design:
The Mangrove Jack 3.65 "V" nose punt is designed with seaworthiness and stability in mind, when on the move out fishing or crabbing. With her high topsides and swivel seats for comfort, the bench seats are designed to provide full buoyancy and storage compartments, capable of supporting the boat in the event of swamping.
The large foredeck, measuring 1064mm (3ft-6in) in depth, provides a great area for casting nets and storing the crab pots. Easy access to the lockers beneath the foredeck, is provided by two large flush deck hatches for all the necessary boat gear (anchors/ warps life jackets etc).
Moving aft, standing on the level cockpit sole, the spacing between the foredeck and the middle seat is 758mm (2ft- 6in) , providing ample room for the everybody when out and about. The midship seat also incorporates a storage compartment for all those drinks/ food etc.
Throughout the boat, along the topsides panel, the Mangrove Jack "V" nose punt includes built in plywood side pockets for all those fishing bit's and pieces.
The spacing between the aft seating arrangement and the middle seating arrangement is 740mm (2ft-5in), providing ample leg room or area for those eskys of ice to store the "catch of the day".
The rear seat, moved away and forward of the transom, allows for a engine well between the rear seat and the transom. This allows for easy cleanup's in the accidental spillage of fuel or oils. With room between the rear seat and transom this allows for comfortable handling of the boat without feeling like the motor is tucked up under your armpit.
Overall the Mangrove Jack 3.65 "V" nose punt is designed to be very comfortable, stable and seaworthy, and most importantly-practical.
Performance
Running through HullSpeed (a part of our Maxsurf ship modeling program suite), the result is a light hull built in our standard material epoxy-glass-plywood composite construction. The deadrise is 45 degrees at the cutwater, about 10 degrees @ midship and 4 degrees at the transom, the Mangrove jack 3.62 has enough vee to handle choppy seas without problems and her moderate beam produces great stability and lift for planing at low speeds. She also incorporates a "V" chine flat for stabiltiy and "on the rail" turning ability.
As the chine rise is very progressive, the Mangrove Jack 3.62 does not have an obvious hump in its transition from displacement speeds to planing, resulting in a good moderate speed boat. Overall, the Mangrove Jack 3.62 is able to maintain moderate speeds between planing and displacement without pushing a huge bow wave.
Materials
e following list of materials is approximate and intended for calculation of approximate costs. We offer no guarantees of accuracy.
The list is for all timber in the construction of hull, deck and interior, including building stocks, temporary bracing etc. Allowance has been made in the quantities for about 20% wastage.
These figures allow for building with 1/4" (6mm) & 3/8" (9mm) Meranti, Hoop pine or Gaboon plywood for the hull and interior.
STRUCTURAL PLYWOOD OR PARTICLE BOARD
8ft by 4ft (2.44 x1.22m) 12mm (1/2") - 2 sheets
MARINE PLYWOOD
8'x4' (2.44x 1.22m -
6mm (1/4") - 7 sheets
9mm (3/8") - 1 sheet
SAWN PINE (for building stocks etc)
50X 75mm (2"x 3") (set up rails- use pine stud material) - 3.65m (12') x 2 plus 4 lengths of 553mm (1' 9") for the cradle crossbeams
Hoop Pine, Oregon or similar,
30x19mm (1-1/4"x3/4") (sheer clamps) -4 m (13') x 2
RESIN & GLASS (for coatings and reinforced areas)
Epoxy resin & Hardner -
West System, FGI R180/ H180 or Bote Cote - approx 12 kg
200g/sq.m cloth fabric - 20 sq.m
Glue powder 5 kg
Fairing powder 5 kg (Q-cells, Microballoons or similar)
2 Litres of Part A High Density expandable foam
2 Litres of Part B High Density expandable foam
Construction
The requirement of the Mangrove Jack 3.65 "V" nose punt was simple. It had to be light, quick to build, easy on the pocket, and yet still retain its strength, seaworthiness and performance. The Mangrove Jack 3.65 , designed to ABS Power Boat scantlings, is built of Marine plywood Sandwiched in epoxy, and directional E-glass fabrics using the Stitch & Tape method, the overall design results in a stronger, tougher and more durable "Composite" boat, while still retaining its lightweight construction.
The Mangrove Jack 3.65 "V" nose punt is designed with full seat bulkheads, every "compartment" is self contained or, you can install on/ off drainage from front to rear. This means if you happen to spill water or fuel in the aft compartment, it stays there! It doesn't "swish" around the rest of the boat, covering everything and making an oily mess. The same applies to all areas within the boat. Everything is contained!
Overall, the Mangrove Jack 3.65 "V" nose punt is lighter and can be built for just a fraction of that of a purchased alloy boat of similar dimensions.
Plans
Click the image above for a Plan sample
Plans for the Mangrove Jack 3.65 are extremely comprehensive, with 6 sheets (D size or 2ft by 3ft) of drawings, complete written specifications and builders manual. Please read our Back Up Policy. This is an ideal project for the first time boat builder.
Drawing #
Drawing Description
1
Arrangement plan & Profile
2
Cradle Construction & Setup Sheet
3
Laminate Schedule & Construction Sheet
4
Construction Profile & Plan Sheet
5
Panel Meaurements & Lofting sheet
6
Plywood layout sheet
All plans provided are drawn on 2ft by 3ft sheets
The plans also include a materials & construction manual
