Pi Marine & Engineering Huai Yai - Boatbuilder Guide

Pi Marine & Engineering is an established custom boatbuilder and marine engineering shipyard based at Navalian Dock Yard in Huai Yai, specialising in naval architecture, composite hulls, and aluminium vessel construction.

Operating within the Navalian Dock Yard industrial compound along Highway 331 in Huai Yai, Pi Marine & Engineering provides full-cycle vessel design, construction, and refit services. The yard employs qualified naval architects and marine engineers to design and construct a diverse portfolio of craft, ranging from commercial passenger catamarans and patrol vessels to private sailing yachts and motor cruisers. Fabrication centres on marine-grade aluminium and glass-reinforced plastic (GRP) composite hulls, alongside modern electric vessel (EV) designs and zero-emission powertrain integrations.

A notable benchmark project from the yard is the EGAT Chonlapat 1, a 12.9-metre all-electric passenger catamaran built for the Electricity Generating Authority of Thailand under Thai Marine Department standards. Engineered for zero-emission passenger transport, the vessel is powered by twin 35-kilowatt electric motors and a 54-kilowatt-hour battery bank, accommodating 15 passengers and three crew members. Alongside new builds, the facility undertakes structural modifications, transom extensions, commercial repainting, and mechanical overhauls for craft operating across the eastern seaboard.

Visits to the shipyard are technical and consultative rather than recreational. Prospective vessel buyers, charter fleet operators, and private boat owners arrange site meetings to review CAD hull drawings, examine naval architecture specifications, or inspect active fabrication bays. The facility directly suits clients seeking bespoke marine engineering, structural aluminium welding, or specialised electric propulsion systems outside of standard mass-production boatyards.

What's There

Pi Marine & Engineering operates out of an integrated production facility inside the Navalian Dock Yard compound, arranged into specialised zones to handle full-cycle custom boatbuilding, engineering refits, and electric vessel conversions.

The technical design office functions as the development base where qualified naval architects handle 3D computer-aided design, structural planning, and hydrodynamic calculations. This space plans hull lines and weight distribution for diverse builds, ranging from private motor yachts to commercial tour catamarans and patrol craft. Immediately adjacent, the main metal fabrication bay is equipped for marine-grade aluminium work. Here, shipwrights cut, shape, and weld plate aluminium into structural ribs and hulls, accommodating projects that extend from small workboats up to 20-metre electric catamarans and passenger ferries.

The facility also maintains a dedicated fibreglass workshop for glass-reinforced plastic (GRP) moulding, composite construction, and structural repairs. Mechanical engineering and systems fitting take place in an assembly and rigging bay, where technicians install conventional inboard diesel engines, outboard configurations, and lithium battery banks for electric propulsion setups. Completing the layout is a sheltered painting and refit shed, used for hull fairing, protective polyurethane marine coatings, and anti-fouling applications for newly built craft alongside returning vessels undergoing hull extensions or transom upgrades.

Getting There and Logistics

Pi Marine & Engineering operates its primary manufacturing facility at Navalian Dock Yard, located at 900/10 Moo 10 along Highway 331 in Tambon Huai Yai, Bang Lamung District. Positioned inland within the rural industrial belt of Chonburi province, the shipyard sits roughly 28 kilometres south-east of central Pattaya. Driving from downtown Pattaya typically takes between 35 and 45 minutes, depending on traffic, using either the Route 7 motorway extension or local routes across Huai Yai to the Route 331 corridor.

Public transport does not serve this rural stretch of Highway 331, leaving private road transport as the practical option. Ride-hailing taxis through apps such as Grab or Bolt from central Pattaya generally cost between 400 THB and 700 THB each way. Because return cars are scarce along the 331 corridor, visitors should arrange a two-way private hire or negotiate for the driver to wait on site. From Bangkok's Suvarnabhumi Airport, the drive covers approximately 125 kilometres via the Route 7 motorway and takes around 90 minutes. U-Tapao Rayong-Pattaya International Airport lies roughly 30 kilometres to the south along Highway 331, taking about 30 minutes by car.

Because Pi Marine operates as a working engineering shipyard within the Navalian Dock Yard compound rather than a walk-in marina or retail showroom, site access is restricted strictly to scheduled appointments for vessel buyers, fleet operators, and project consultants.

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