Koalen 18 Study Plans PDF
Pocket cruiser and traditional gaffer 18′ 1/2
|Hull length / waterline||5.64 / 5.05 m||Sail area||23.3 m²|
|Breadth / waterline||2.22 / 1.82 m||Outboard motor||6 ch|
|Draught||0.80 m||Design category / Crew||C4 / D5|
|Light weight (including motor) / ballast||800 / 300 kg||Building time||800 hours|
Koalen 18 is a small traditional gaffer, inspired from traditional fishing boats of Northern Brittany with the plumb stem and moderately raked transom. She is an enlarged version of Koalen 17, a boat initially built by Icarai boatbuilder in France. The first Koalen 18 was built by Grand-Largue boatbuilder in France.
Koalen 18 is planked over a crisscrossed plywood structure including backbone and bulkheads. A developed panel makes the bottom planking and the side planking is made of two layers of 4 mm plywood, laid vertically on stringers. Once again we got confirmation that this process gives both a sturdy hull faster to plank than strip planking. We decided to have the ballast inserted inside the plywood backbone. We used lead pigs or lead scraps and epoxy. Therefore, the keel is hydrodynamically very clean and, despite a moderate draught, and gives both an efficient lateral plane and good stability.
Two rigs are proposed, a gaff cutter rig, which gives a very traditional look, or a more simple gaff sloop rig.
To have a serviceable cabin in such a small boat and keep an elegant line is not easy. But not having any centreboard case allows a minimum of seated comfort, to have two normal size berths, a stowage for a Porta-Potti toilet under the cockpit and enough storage space for a small cruise with a camping stove. The aim of Koalen 18 is mainly to be a day-boat with a cuddy, but it is possible for two people to spend some nights onboard, allowing to discover more remote areas than a simple day boat allows. Koalen 18 is a pocket cruiser easy to trail behind a medium-sized car, but requiring some handling facilities to have it into the water.
Koalen 18 has an outboard motor well aft of the cockpit, located at helmsman reach. The designer may also draw a diesel version if required.