Design parallels the single-handed Laser on all aspects.


After years of development, the JS-4300 was designed specifically to parallel the single-handed Laser on all aspects of simplicity.

Fundamental to this, the JS-4300 was created as what will become an aesthetic timeless classic.

The JS-4300 is ‘today’s’ Laser.

How the JS-4300 compares to the Laser:
  • Is longer on the waterline by approximately 500mm
  • The maximum effective waterline beam is greater than the Laser by approximately 200mm. This has the effect of having a greater ‘righting moment’, making the JS-4300 more stable.
  • The appendages (rudder and centerboard) are of a high-aspect ratio, and low volume, compared to the Laser. This yields a superior lift-to-drag ratio and superior controllability and balance.
  • The prismatic coefficient is considerably higher than most contemporary designs of similar type. This equates to greater top-end speeds.
  • The hull-deck geometry has been ergonomically designed to eliminate painful “gunnel bum”.
  • Laser replica sail and spar configurations are interchangeable with JS Yachts design proprietary configurations.
JS-4300 dinghy


4.30 metres
1.38 metres
Sail Area Options:
6.5m2, 8.0m2, 9.5m2
Sail Cloth Options:
Dacron, Mylar
Spar Options:
Alloy and/or Carbon Composite
GRP / Carbon Composite
Windseeker, Turkey
Hull / Deck Moulding, Daggerboard and Rudder from $6,500 AUD


The JS designs: JS-4300, JS-4600, JS-4700, JS-4800 and JS-4900 represent a body of work (design, evaluation and engineering) that has been carried out over the past 5 years. All designs contain the same “core values” of the famous Laser – ‘Simplicity, and minimalist’

Sail and spar options allow for sailors’ skill, stature and weight.

Depending on skill level and sailor’s size, sail and spars are optioned with sail area and spar dimensions to suit. For entry level, to minimize costs, dacron sails and aluminium spars can be used. This suits beginners and recreational sailors. For advanced level performance sailors, carbon composite spars and mylar sails are available.

Single or double-handed crew potential
The JS-4300 is primarily designed for single-handed sailing. The JS-4300 can also be sailed double handed by junior sailors.
Deck and spar equipment is ergonomically user-friendly for all skill levels.

Independent of sailor’s size and skill level, placement of all control lines for adjustment allow for easy access and operation.

Structural lifelong durability

Material selection and scantling (specific dimensions for structure) have been engineered to ensure lifelong integrity of all parts of the JS-4300 – hull/deck, appendage mouldings and spars.

Low cost maintenance: minimal/non-complex

The number one rule of boat design/building is that there should be easy access to all mechanical fastenings and equipment. The core value of ‘simplicity’ underpins the design of the JS-4300. Most of the fittings can be easily accessed for service and/or replacement. The JS-4300 features two proprietary inspection ports and one catalogued inspection port that provides storage for personal items.

Built for both recreation and performance sailing.

Spar and sail plan selection, along with control-lines set up, allows for sailors to achieve their potential sailing and handling skills of the JS-4300.

The JS-4300 concept supports novices/beginners, and extends to the most advanced and experienced Olympic sailors. Every sailor can enjoy the JS-4300 at a recreational as well as at a superior performance level.

Vang, cunningham and outhaul: single or split (port & starboard) set up

The standard set up of the JS-4300 is the same single line set up as on the Laser. Optional set up for a split system for the JS-4300 is by way of attaching additional blocks and jam cleats. Positions for these are marked up on the deck moulding, should the sailor choose this option after purchase. Alternately these can be factory-fitted.

Toe straps adjustable to suit hiking style and sailor size

The toe straps selected for the JS-4300 provide the best connection for the JS-4300 boat’s dynamics. For smaller sized sailors, an additional toe strap (port and starboard) is optional. The JS-4300 toe straps allow each sailor to hike hard, and for longer, whilst keeping your feet relaxed.

Hull and appendage geometry optimized for sail plan – helm and balance properties

The JS-4300 has undergone rigorous evaluation of hull form and centerboard and rudder configurations. Developed from the original JS-4300 hull form, a set of strakes has been fitted. These strakes increase side force, and dampen pitch and heave. Second to this, the strakes significantly deflect spray. Of particular note, the strakes, by way of suppression of the bow wave, reduce form-drag and increase the top-end speeds. In a capsized situation, the strakes also act like grab rails to assist the sailor in righting the boat.

Spar material: optional – carbon composite and /or aluminum

Depending on skill level and sailor’s size, spars are optioned with spar dimensions to suit. For entry level, to minimize costs, aluminium spars are available ie beginners and recreational sailors. For advanced level performance sailors, carbon composite spars are available.

Sail material: optional – mylar or dacron

Depending on skill level and sailor’s size, sails are optioned with sail dimensions to suit. For entry level, to minimize costs, dacron sails are available ie beginners and recreational sailors. For advanced level performance sailors, mylar sails are available.


The JS-4300 mainsheet is centrally located on the boom with the purchase system at a 4:1 ratio.

Rudder configurations: fixed or pivoting

Standard rudder configuration on the JS-4300 is fixed. An optional pivoting rudder configuration is also available. The pivoting rudder configuration is similar to the Laser.

Hull and deck structure: cored composite carbon & glass

The JS-4300 hull and deck mouldings are a cored composite carbon and glass laminate structure. The JS-4300 hull and deck is chemically and mechanically fastened. The gunnel geometry on the JS-4300 has a large radius to accommodate crew comfort and windage drag reduction. This ergonomic design aspect specifically eliminates painful “gunnel bum”. Additional reinforcing laminate is located in way of all mechanical fastenings.

Optional Upgrades & Accessories

  • Composite Carbon Spars
  • Mylar Sail (size optional)
  • Pivoting (swing) or cassette rudder assembly
  • Dual (port/starboard) control line set-up
  • Launching trolley (316 stainless steel)
  • Ripstop transport top cover
  • Ripstop transport undercover
  • Ripstop regatta top cover
  • Padded comb bag
  • Padded rudderstock/tiller bag
  • Mast padded cover – bottom part
  • Mast padded cover – top part )
  • Padded boom cover

Other Dinghies in the Range



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