Designing the Adjustable Tuttle Box

Michael McKinley

Tuttlebox.com

Built on a Proven Standard

In the early 1980s, Larry Tuttle created the Tuttle Box, a connection standard defined by strength, stiffness, and reliability.

After four decades, the Tuttle Box continues to be a mainstay for top athletes pushing their limits across high-performance wing-foiling, kite-foil racing, parawinging, downwind foiling, and windsurfing.

The Adjustable Tuttle does not replace that legacy, It extends it.

A Fixed System in a Variable World

The classic Tuttle Box is fantastic, but it’s fixed.

Ive been an avid foiler for over a decade in the San Francisco bay area. Since 2020 I've been designing custom foil boards to work perfectly with MikesLab foils. Usually I design a custom board to match the specific goals of an individual rider. I can calculate the exact position of the Tuttle Box down to the millimeter.

That precision is powerful — but it comes with a tradeoff. Switch foil brands and you're compromising performance. Want to change mast angle for different conditions? You're improvising shims.

Tracks offer more adjustability, but at the cost of weight, stiffness, drag, and simplicity. The question became: can I build an Adjustable Tuttle Box without losing the magic?

A New Approach from First Principles

I spent two years refining the Adjustable Tuttle from a clean first principles design. The system had to be entirely compatible with the legacy Tuttle specification while offering the adjustability that I needed. I continuously refined and tested the lamination schedule and adjustment system. Every iteration was pushed until I was confident it matched or exceeded the strength and stiffness of a traditional Tuttle Box. I’ve done extensive testing in the lab and on the water to gain confidence in the design. I worked closely with Ken Adgate, Kyle Touhey, Josh Waldman, and Kevin Gorman during the pre-production phase to gather insight from real world testing. The breakthrough came when I realized I could match the stiffness of the original Tuttle Box without a substantial weight penalty.

The new Adjustable Tuttle system offers

Full compatibility with standard Tuttle Masts
2 inches of fore–aft adjustment using position shims
Adjustable rake changes using angle-specific shims

I knew that we had created something cool when Ken Adgate and Kyle Touhey came off the water with rave reviews: The Tuttle interface stays the same, the ride feel is unmatched....but now it’s tunable!

Continuous Development

At Tuttlebox.com we are excited to be partnering with Slingshot to bring the Adjustable Tuttle Box to a wider audience. We are actively extending the core technology of the Adjustable Tuttle into other areas of foiling and we are dedicated to carrying the Tuttle legacy far into the future.

Feel free to reach out to us directly with any questions or special requests.

Early on water stiffness testing of the prototype Adjustable Tuttle (2024)