Cathedral (tri-hull) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/cathedral-tri-hull/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)
Basis: Design rules and figures from the cited sources; example geometry by Xem Studio
Catalog version: 2026-10-20

Sizes: see table below
- A tri-hull is a V hull with sponsons built into the bow, so it looks like three hulls forward but is one solid hull aft (Boatsetter).
- The sponsons add buoyancy, width and stability, making a good fishing and deck-boat platform, but the triple bow pounds in chop for a rough, wet ride (Boatsetter).
- Richard Cole designed the first tri-hull in 1958 at Thunderbird Boats; most builders moved to deep-V hulls in the 1980s (Boatsetter).
- Used on: Wellcraft Airslot, Thunderbird tri-hulls.
- The file is a reference example built by Xem Studio from the numbers above (Reference RC mono: 585 mm length and 20 deg transom deadrise (SV Design Stealthwake data); 181 mm is an unlabelled width in the same source's deadrise diagram.). Sizes the sources do not fix are illustrative; scale the example to your own vehicle.

parameter  value or range  source
First design  1958 (Richard Cole, Thunderbird Boats)  Boatsetter
Current use  deck boats; fishing boats under 18 ft  Boatsetter

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Boatsetter: What is a tri-hull boat? — web — Publisher's page; dimensions are facts — https://boatsetter.com/boating-resources/what-is-a-tri-hull-boat

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/cathedral-tri-hull/index.json
API: https://xemstudio.com/api/geometry?object=cathedral-tri-hull