Lightweight, Traditional looking, Open Power Cruiser

Breaking camp early, the early morning fog lifts as you slowly explore and work your way through the endless estuaries, inlets and headlands. The smell of the coffee and the warmth of the mug within your hand, reminds you of the simple pleasures of life. A life away from the endless grind of work and suburbia.

Exploring your way around a small headland, you notice a small break within the giant boulders. An opening finally appeared with clear waters, a sandy beach, and grasslands behind. The excitement begins to build as the kids begin jumping up and down and pointing. We've finally found our next campsite and even better, there's no one around for miles

Overview

The BOSUN'S MATE 23 is designed to be versatile and functionable, fulfilling a number of tasks and requirements and, yet remain pleasing to the eye. The BOSUN'S MATE 23 plans are large scale drawings printed on 2' by 3 ft sheets or D size and are drawn to a very high degree of accuracy in both metric and imperial measurements. We also provide building notes and material list.

Overall, the BOSUN'S MATE 23 offers a great opportunity for those weekend fishing & camping adventures, or a reliable workhorse for those professionals on the water. But just as important as all the above, it's also designed for those on a tight building budget.

Design Brief

Approached by Warren Jacobsen of JACOBSEN TIMBER BOATS, we were asked if we could design a boat of similar nature, only lighter in construction, to the one he was building at that time, a heavy "traditional plank on frame" boat.

With rising fuel costs, could we design a workboat to suit his professional client's needs, i.e. a fisherman's workboat, that would not only suit that market, but would also appeal to the recreational fisherman and coastal explorer market. Overall, our main priority had to a simple open plan design, with the priority being the reduction in fuel consumption without, compromising the strength, durability and safety.

On discussion the points noted were:

• It had to be an open boat,
• Length overall - around 23 ft (7m)
• Beam overall 6-7 ft (1.82 - 2.13m)
• A recreational boat for camping and fishing expeditions
• Workboat for Professional net fisherman/ crabbers and the like.
• A multitask design.
• Loads of storage compartments and seating
• Lighter in construction
• Easily built.
• Easy to handle getting on and off the trailer.
• Long range
• Minimal Horsepower requirements
• Less fuel consumption
• The fraction of the cost of a similar size new alloy power boat.

Overall, it had to be a simple design, pleasing to the eye, but capable of many concepts and tasks.

Arrangements:

The BOSUN"S MATE 23' cockpit length is 19ft (5.79m) long! With its all round seating and storage compartments beneath, it is well laid out with heaps of room for those family expeditions or as storage for the professional. The seating height is 16 in (.406m) above the sole, but allowing for a 2"(50mm) cushion or squab, she'll give a comfortable seating height of 18" (457mm). (In other words, not having your knees in your face as some boats do!)

With a constant seating width of 19" (482mm), the BOSUN"S MATE 23 has got ample room to just lay about sun baking or to just curl up and read a book, waiting for the fish to strike the bait.

In regards to freeboard, at the miship section her height is 2ft- 4in (696mm), whilst at the bow where it counts, her height is 3ft - 2in (973mm).

All in all, the concept had to be kept simple, yet fully functional with storage everywhere, to suit your personal needs or desires.

Performance

Running that through Maxsurf (our ship modeling programs), the result is a light hull built in our standard material epoxy-glass-plywood composite construction. The deadrise is 52 degrees at the cutwater, about 17 midship and 8 degrees at the transom, the Bosun's mate has enough vee to handle offshore seas without problems and her narrow beam produces less slamming than a wider hull.
The chine rise is very progressive and the Bosun's Mate does not have an obvious hump in its transition from displacement speeds to planing. She is a good moderate speed boat. Overall, the Bosun's Mate 23 is able to maintain moderate speeds between planing and displacement without pushing a huge bow wave.
Designed as a work boat and not a speed boat, the Bosun' mate 23 can accept an engine as large as 50 HP however, we recommend to install a 9.9 Yamaha 4 stroke with a work prop for torque for max effieciency and low fuel consumption.
	click images above to enlarge

Displacement Speeds Vs HP @ 60% Propeller Efficiency

Materials

The 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 10% wastage, with the exception of the building stocks and chipboard, which are net.

These figures allow for building with 3/8 in (9mm) plywood skin for hull, floors, frames and interior and 6mm for the deck surrounds.

CHIPBOARD or MDF 
8ft by 4ft (2.44 x1.22m) 16mm (5/8") - 1 sheet 

MARINE PLYWOOD 4'x8' (1.22x 2.44m)
6mm (1/4") - approx 14 sheets
9mm (3/8") - approx 11 sheets

SAWN PINE (for building stocks etc) 
25X125mm (1"x5") (rails and braces) - 12.8m (42') 
50x19mm (2"x 3/4") (frame supports) - 20m (66')

Hoop Pine, Gabboon ply or similar, selected, free of knots, shakes fractures etc
19x19mm (3/4"x3/4") (Headers & sheer clamps) -32 m (107')
19x30 mm (3/4"x1 1/8") (Cockpit Sole stringers) - 12.8m (42')
38x42mm (1 1/2"x1 5/8") (Rubbing strake) - 15m (47 ')

RESIN & GLASS (for coatings and reinforced areas)
Epoxy resin - 48kg 
450g Double Bias - 31sq.m 
Cabasil (glue powder) - 10 kg 

Construction

The BOSUN'S MATE 23, designed to ABS Power Boat scantlings, is built of Marine plywood, using the Stitch & Tape method. Built upright from the start, the BOSUN"S MATE is sandwiched in epoxy, and directional E-glass fabrics.

This results in a stronger, tougher and more durable "Composite" boat, yet still retaining its lightweight construction.

Further more, she can be built for just a fraction of that of a purchased alloy boat of similar dimensions. In today's present world of tight budgets, you can now afford to build the BOSUN'S MATE 23 at your own leisure, but also within your own budget.

Plans

Click the image above for a Plan sample

Plans for the Bosun's Mate 23 are extremely comprehensive, with 9 sheets (D size or 2ft by 3ft) of drawings, complete written specifications and builders manual.

Drawing #	Drawing Description
1	Profile & Arrangement Plan sheet
2	Lines plan sheet
3	Cradle & Set-up Construction sheet
4	Bulkhead & Frame Construction sheet
5	Laminate schedule & Constrution sheet
6	Construction Plan & Profile
7	Construction Sections
8	Panel Construction & Lofting Sheet
9	Panel Construction & Lofting Sheet