The Duotone Foil Assist adds electric power to your setup.
The Foil Assist bridges the gap between traditional foiling and e-Foiling. Unlike an e-Foil, where the motor provides continuous propulsion throughout the entire ride, the Foil Assist delivers temporary electric propulsion to help you get up on foil, motor out to the waves, take off in light conditions, or link bumps more easily on downwind runs. Because the system is integrated into a standard hydrofoil setup, it remains significantly lighter, more modular, and more versatile than a traditional e-Foil, allowing you to use your preferred board and foil. This preserves the natural, responsive feeling of foiling while allowing you to ride in a wider range of conditions, explore new spots, and progress faster.
To suit different riding styles and ambitions, we offer three integrated mast options. The Assist masts provide electric assistance for surf, wing, wake and downwind foiling, while the Foil Cruise provides continuous electric propulsion for relaxed flatwater cruising, riding small swell and learning to foil.
:grayscale(false):quality(10):blur(20) "Matahi Drollet foiling on a wave")
:grayscale(false):quality(10):blur(20) "JeffreySpencer_MatahiDrollet_Midfish_FoilAssistDLAB_Duotone_DTE_Tahiti_by_Ben_Thouard_ 521834")
:grayscale(false):quality(10):blur(20) "Wing Foiling with the Foil Assist")
:grayscale(false):quality(10):blur(20) "Duotone-Electric-MidFishAir-EdgarUlrich-2027-Venezuela-TobyBromwich-2035")
Choose your Foil Assist Set
Use your existing foiling equipment with our Foil Assist Masts. All our masts are compatible with foil boards featuring standard US foil tracks. Our aluminium masts can also be paired with a wide range of Duotone and third-party foils using our fuselage adapters.
On the Duotone Foil Assist, the batteries are integrated into a lightweight, buoyant eHarness instead of mounted on the board. This keeps your board and foil setup light, balanced, and responsive while still giving you full freedom of movement. The smartwatch-style Watch Ring Remote keeps your hands free for paddling, duck diving, popping up, or handling a wing. The compact batteries connect directly to the battery box without the need for tools, making installation and battery swaps quick and easy.
All accessories are also available separately, whether you need an additional battery set or a second eHarness in a different size.
:grayscale(false):quality(10):blur(20) "Leo Etienne surfing on a wave")
THE FOIL ASSIST
The Foil Assist is designed to enhance your foiling experience across multiple disciplines, including prone, downwind, wake and wing foiling. With the motor mounted high on the mast, you can motor out and get on the wave, then pop up on foil and enjoy the natural feel and glide of your foil. Once you're flying, you can switch off the motor and the propeller blades fold away, allowing for low drag.
:grayscale(false):quality(10):blur(20) "Edgar Ulrich foiling on flatwater in Venezuela with the Foil Cruise Mast")
THE FOIL CRUISE
The Foil Cruise Mast is designed for relaxed flatwater cruising with continuous electric propulsion. Featuring a lower motor position, it delivers smooth, consistent thrust that helps you get onto foil quickly and maintain a stable, controlled ride. Whether you're riding across a calm lake, exploring coastal waters or building confidence in small bumps, the Foil Cruise makes foiling easy and accessible.
With the Cruise setup, you can choose between two battery placement options: on the eHarness or on the back of the board. The board-mounted option is particularly suitable for beginners. To mount the batteries on the board, you'll need the Battery Box Mounting Set, available under Accessories.
:grayscale(false):quality(10):blur(20) "eCruiseFoil_BT54961")
:grayscale(false):quality(10):blur(20) "Matahi Drollet foiling on a wave")
:grayscale(false):quality(10):blur(20) "Mo Chauvin pulling the Foil Assist Gearbag")
:grayscale(false):quality(10):blur(20) "Girl putting in the fuselage adapter")
Frequently Asked Questions
The battery runtime depends on several factors, including your skill level, weight, riding conditions, board size, used speed level and the efficiency of the foil you have mounted; it ranges between 30 and 45 minutes.
The Foil Assist Charger powers both batteries in about an hour, getting you back on the water in no time. It can also discharge the batteries to an optimal storage level (around 50%) to help prolong battery life.
When not using the batteries, we highly recommend storing them at a mid-charge level. When you’re ready for your next session, it will take only about 30 minutes to fully charge both batteries.
:grayscale(false):quality(10):blur(20) "DTE Whats included in your Foil Assist Set with Terence")
The setup process takes only slightly longer than setting up your prone or wing foil gear. You mount the Foil Assist Mast just like any other foil mast, with the only additional step being securing the cable to the board and sliding the fuselage adapter into the mast.
Next, attach the power cable and safety leash to the eHarness, plug in the batteries, close the battery box and zip up the neoprene cover, put on the Watch Ring Remote, and you're ready to ride.
:grayscale(false):quality(10):blur(20) "DTE How to set up your Foil Assist with Terence")
We offer a smartwatch-style remote with a finger ring controller to keep your hands free for paddling, duck diving, popping up, carving, or wing handling. Simply activate the motor with a double-click, then fine-tune your speed using the plus and minus controls.
We chose this Foil Assist remote instead of a classic trigger remote to keep the overall experience as close as possible to non-powered foiling. It typically takes one or two sessions to get used to operating the remote.
The warranty applies within the legally prescribed scope of two years for all Foil Assist products. We do not offer a 6‑month warranty extension for Foil Assist products, except for foil boards such as the Midfish or Midfish Air.
The integrated Foil Assist masts are only 1.2 kg heavier than a standard Duotone mast. The carbon mast weighs 3.0 kg, while the aluminum mast weighs 3.55 kg.
Each battery weighs approximately 1 kg, and the eHarness weighs around 1.8 kg. This means you're carrying about 4 kg on your waist, which is barely noticeable once you're up on the board and riding.
Yes, the Foil Assist masts are compatible with all foil boards that use standard US foil tracks. The aluminum masts are also compatible with foils from most major brands when used with our fuselage adapters. The carbon mast is only compatible with Duotone, Armstrong, and Takuma foils through our specially designed fuselages.
:grayscale(false):quality(10):blur(20) "DTE Product Tests")
:grayscale(false):quality(10):blur(20) "Flatwater_Cuising_Jeffrey_BT50874")
:grayscale(false):quality(10):blur(20) "Leo Etienne foiling on a wave")
:grayscale(false):quality(10):blur(20) "Mo Chauvin surfing on a wave with the Foil Assist")
:grayscale(false):quality(10):blur(20) "Jeffrey Spencer holding the Foil Assist AL and Midfish Board and checking the spot")