Boat Design Net forum

Proposal: Pneumatic Emergency Aeration System for Catamaran Stability - DOI: 10.5281/zenodo.22360760 My name is Yermek Kobulbayev from Semey, Republic of Kazakhstan. I would like to present my invention: Pneumatic emergency aeration system of Kobulbayev E. for self-recovery of stability of multi-hull vessels (catamarans) version 2 supplemented The system is designed for emergency self-recovery of stability on multi-hull vessels. The full technical description is officially published and... Read more

In the process of choosing a rig for my future cat. Would like to get some input from engineers and owners. The cat is a 10.5m, demountable, with a central pod. Initially I was keen on a 3 stay rig like Pic #3. I need a safe rig with the sail area broken down into manageable areas and loads. The 3 stay rig was presented to me be an experienced multihull sailor and it seems the right fit for my needs. But I am wondering about the structural benefits of an A-frame mast instead of a single... Read more

Good evening All A very quick question, I have a run of approx 5.5m from battery's to Motor. Motor is a Volvo Penta AD31B and I have a twin Battery system mounted in the cabin. What size cables do I need use from batteries to motor. These are for the main start cables.

Hi everyone, I mentioned a few times that I was working on a new(ish) design for a cruising rig, a rig that I though off since I built a 12.5m cat in 2002. Basically my cat cannot be sailed with the main only; now, I know that others can, however this is not the only point, what got me thinking is: 1.Mains can only be reefed upwind (where there is more wind), this can also be dangerous if you were running and left too much canvas up too late and, is never a one man job. 2.The boom is a... Read more

Hi all, We’re about to begin building the mold for a 29 ft center-console catamaran and I’d appreciate a sanity check on the resin choice and proposed laminate before we commit. The mold will be one piece, incorporating both demi-hulls and the tunnel, with approximately 55 m² of tooling surface. Target service life is around 50 pulls. Our shop is in a tropical climate, typically 28–32°C with high humidity year-round. Construction will be by hand layup with two experienced laminators... Read more

Hi all I am looking for advice on what to consider when converting a plan to skin on frame construction. sailing and rowing designs upto 16' long. I'm thinking of boats like a peapod, or shetland yawl etc. I will be using an unstayed lug rig. Skin on frame due to ease of construction, material cost, and most importantly light weight for home storage/car topable etc etc So far I realise that they are obviously a lot lighter, so would sit higher in the water and thus potentially be unstable... Read more

Hi everyone, On the chart, you see only one of the many unique properties of the hull during the acceleration phase , which carries undeniable commercial and research value. The data is deliberately cropped and presented strictly in dimensionless units to protect proprietary geometry from reverse engineering and automated parametric optimization. This displays the performance analysis of a new hull architecture covering the displacement range and the unsteady dynamics of... Read more

Looking for commentary/critique (aside from, "don't design it yourself"). I have put together a design for a catamaran to meet my list of requirements: 1. catamaran, max 34 ft. LOA, 21 ft. beam 2. good bridgedeck clearance…32 inch minimum 3. minimum open bridgedeck, well back from bow and stern 4. center of gravity at or below bridgedeck, with all tankage, engines, food storage near waterline 5. epoxy-cedar strip hull bottom/ply on frame above (as in Woods Sagita/Eclipse)... Read more

Hi, I'm currently building a modified version of the Boat Builders Central Texas Sled (TX18). I've increased all dimensions by 10%, so now have a 20ft boat (designer has approved this). The hull is heavier than designed due to more glass layers and the consol design. I'm planning to run a 140HP Suzuki (at our altitude it's closer to 115hp I'm told). As the hull is very flat towards the stern I am beginning to worry about the possibility of blowouts if I need to make an emergency turn at... Read more

Designing and building a custom sailing catamaran...thinking.... My question (and I think this applies to any sailboat, really)... Why have a main? Why not set the mast way back on the boat and just use multiple (say 3 in my case) roller furling headsails? Cheaper (yes, agreed, 3 drums and 3 headsails but no boom, no mainsail, no main halyard winch, no lazyjacks, no traveler, no sail cover, no mainsheet blocks, etc.....and (very key to me) much much quicker to set sails (just unroll... Read more

Hi this is my first post here. I want to learn more about what makes the Mini Transat scow yachts so fast and can those benefits translate to the larger IMOCAs.

Does anyone have info on a Globemaster 26 Tri designed by Arther Piver? Just bought one and want to bring her back to life.