Library › Boat design › Fin keel with ballast bulb

fin keel bulb

fin keel bulb: 420 mm deep, 60 mm chord, NACA 00-series foil, bulb Ø40 × 180 mm

Exact dimensions. True size, no printing tolerance added. Threads are plain cylinders at the major diameter.

STEP STL free, Xem Studio Design License — Xem Studio

Let your AI pull this. Add https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.

Set it up →

From the full sheet

Fin keel with ballast bulb: every size, notes, mating features and sources. Why do racing yachts and RC sailboats use a thin fin with a bulb?