Mumby 48 Build — Coastal Boats Cambodia
The Mumby Cyber 48 Sailing Catamaran

Realise Your Dream
Using Our Expertise

Coastal Boats (Cambodia) Co Ltd builds precision aluminum performance catamarans — with BV/DNV certified plate and skilled fabricators in a 700M² dedicated facility.

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700 m² Dedicated factory space in Cambodia
3 Vessels Capacity for simultaneous builds
BV / DNV Certified aluminum plate — Singapore sourced
Mumby 48s under construction Factory expansion Hull number two
The Beginning

Building the Mumby 48 in Cambodia

Aluminum plate is sourced in Singapore and certified BV or DNV. Cutting of bulkheads and frames is also done in Singapore, then shipped to our Cambodia facility for assembly.

  • High quality build to exacting standards
  • Certified BV / DNV aluminum plate throughout
  • Skilled fabricators and coded welders
  • CAD-precut bulkheads and frames
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Mumby 48 aft beam — lofted directly from plans

The aft beam lofted directly from the plans and manually cut

Lofted template

Topside parts lofted onto plywood templates to minimise plate waste

Traditional Craftsmanship

Lofting a Boat: A Visual Guide

Lofting is the traditional method of creating full-scale drawings of a boat’s hull lines — a crucial step in boatbuilding that ensures accuracy and consistency throughout construction. With the Mumby 48 design, bulkheads and frames are precut using CAD software, but a significant amount of manual lofting is still required for a perfect fit.

A flat, smooth surface — such as a large sheet of plywood or a concrete floor — is ideal. If not using a template, the part being lofted can be transferred directly onto the aluminium plate.
A straight line representing the keel of the boat is drawn first. This baseline becomes the reference point from which all other measurements are taken.
Using the boat’s plans and a tape measure, the various lines — waterlines, buttocks, and stations — are transferred from the plan drawings onto the prepared surface at full scale.
Any irregularities or inconsistencies are smoothed out using a batten to create a fair, pleasing hull shape. This step is critical — any unfairness here will be visible in the finished hull.
Once the lines are fair, templates are created for each hull section — stem, stern, ribs, beams, and more. These templates are then used to cut parts from aluminium plate, minimising material waste.
Note: While modern CAD software has made lofting less common, it remains a valued skill for many boatbuilders who prefer a hands-on approach — and for custom sections not covered by the precut parts.
Material Guide

Aluminum vs Fibreglass — Which is Right for You?

Both materials have distinct advantages depending on your priorities. The Mumby 48 is designed around aluminium’s exceptional strength-to-weight ratio and longevity.

Aluminium

The Mumby 48’s construction material

  • Significantly lighter than fibreglass — less fuel, easier handling
  • Exceptional impact strength — ideal for offshore and rough water
  • Lower ongoing maintenance — no gelcoat to polish
  • More affordable to build at this size
  • Fully recyclable and repairable anywhere in the world
  • Noisier — water slap on hull more audible
  • Requires anodising/paint for saltwater corrosion protection
  • Aluminium is the standard choice for offshore performance builds

Fibreglass (GRP)

The production boat standard

  • Smoother, quieter ride — especially in light chop
  • Wide variety of shapes and moulded designs
  • High-gloss gelcoat finish from the mould
  • Heavier — higher fuel consumption and harder to trailer
  • More expensive to build one-off (requires a mould)
  • More gelcoat maintenance — waxing, polishing, osmosis
  • Less impact resistant — collision damage is harder to repair
  • Best suited to production builds and sheltered-water cruising

Our recommendation: For a 48ft offshore performance catamaran built to last, aluminium is the clear choice — lighter, stronger, and repairable in any port in the world.

Build Progress

Construction Process

Follow the Mumby 48 build from first frames/bulkheads to twin hulls in the water.

Aluminium frame and bulkheads

Aluminium Frame & Bulkheads

Building jig — first stage

Mumby 48 aft beam

Mumby 48 Aft Beam

Keel and T-bar — first stages

Lofted template

Lofted Templates

Topside parts cut from plywood template

Topside template

Topside Templating

Minimising aluminium plate waste

Factory expansion

Factory Expansion

New 700m² facility — Cambodia

Hull number two

Hull Number Two

Both hulls now set up

Step by Step

Construction Process Slideshow

Mumby 48 building jig

Mumby 48 Building Jig

First stage in the process — setting up the precision alignment jig

Mumby 48 keel and T bar

Mumby 48 Keel and T-Bar

First structural stages — keel laid and T-bar positioned

Two hulls out of the jig

Two Hulls Out of the Jig

Both hulls now set up and ready for the next phase

Steel frame setup for main beams

Steel Frame — Main Beam Support

Support structure for aligning and fitting the main beams

Cabin aft bulkhead installation

Cabin Aft Bulkhead

Aft bulkhead installed — this also serves as the main beam attachment point

Forward beam installation

Forward Beam Installation

Fitting the forward beam in place

Ready to Build Your Dream Catamaran?

Talk to the Coastal Boats team about specifications, timeline, and pricing for your Mumby 48 build.

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