Surf Foil

A wing under a short board turns weak swell into flight

78 boards · 12 brands · 367 sizes

Surf foiling is surfing on a short board that rides on a hydrofoil, a mast and wing set below the hull. You paddle into a wave as on a surfboard, then the board rises clear of the water and goes quiet, because only the mast and wing stay in the water. Surfers use it on small, soft or mushy waves that a normal board can barely ride, and a handful of big-wave riders tow into huge surf on foils.

A typical surf foil board, 1372 by 480 mm
the typical outline: every board’s shape averaged at the median length and width

The typical board

The typical surf foil board is 1470 × 491 mm, 42 L, with a square tail and its wide point ahead of centre.

1270–1981mm long · median 1470

451–559mm wide · median 491

25–94litres · median 42

2.9length over width, median · derived

Ranges hold the middle 80 % of every size listed · tails: square tail 27, rounded pin tail 21, round tail 18, pin tail 10, swallow tail 2

How It Rides

What moves it

Paddling and the wave's push give the board speed. Once it is fast enough, water flowing over the wing makes a pressure difference that lifts the rider and board out of the water. With only the narrow mast and wing in the water, drag drops so far that a rider can glide along unbroken swell, link several waves in one ride, and pump the board back out to the lineup without paddling. Early stand-up foils were towed by jet ski because they needed outside power to get up to flying speed.

Reading the shape

Surf foil boards are much shorter than surfboards of the same volume: one shaper compares a 4'6" foil board with a 6'2" surfboard of similar volume, chosen because the short package carries far less swing weight. The volume sits under the chest for paddling, so the outlines are stubby: Armstrong's range runs from 4'0½" x 43.8 cm x 5.7 cm (24 L) to 4'11" x 52.1 cm x 7.9 cm (48 L), with a full surfboard-style nose, a squared-off tail for the back foot and a double-concave-to-vee bottom. There are no fins, just a mast box under the rider's feet, and the deck is kept stiff so every movement reaches the foil. Rule of thumb: about 36–40 L for a first board, around 38 L (4'8") for a beginner-to-intermediate surfer, then size down as skill grows.

How to read any board: length and width, wide point, tails, rails, rocker

Wind

none needed

Water

small, soft waves and unbroken swell; also big surf when towed in

Worth knowing

Works best on waves too weak or slow for a normal surfboard, as long as there is depth under the mast.

The Rack

Every surf foil board, shortest to longest, one scale · from the Axis Dock Carbon (880 mm) to the Kalama Gator All Performance 2025 (2616 mm)

All 78 in the catalogue

Good To Know

  1. The idea is older than the Maui tow crew. Daniel Ruben Morgan of Aiea, Hawaii, filed a patent for a 'wave-propelled' surfboard held above the wave by front and rear hydrofoils on 26 October 1970. It was granted on 24 July 1973, and a pedal-steered nose foil replaced the fin. [1]

  2. Rush Randle, one of the first riders to stand on an Air Chair foil with the seat cut off, claimed one ride of 10 miles on a 20-foot ocean swell that lasted 15 minutes. [2]

  3. Tareah Hendricks' 2003 patent for a prone hydrofoil surfboard notes that the Hamilton-style foil board needed outside power, a boat or a kite, to reach flying speed and pull the rider onto the wave. Paddle-in foiling solved that problem. [3]

  4. In March 2017 Kai Lenny crossed the Alenuihāhā Channel from the Big Island to Maui on a hydrofoil board, using only open-ocean swell. The straight-line distance is about 30 miles, but zigzagging from swell to swell took him about 50. [4]

  5. In February 2020, aged 55, Laird Hamilton towed into Nazaré on a foil board during Storm Dennis, on waves of about 60 feet. Kai Lenny, Ian Walsh and Lucas Chianca were out in the same session. [5]

Watch And Read

Who Makes Them

Where And When

Where to watch it

  • Pe'ahi (Jaws), MauiWhere Hamilton, Kalama and Randle first towed foils into waves, and where Rush Randle was photographed foiling in 2003.
  • Praia do Norte, Nazaré, PortugalLaird Hamilton foiled waves of about 60 ft here in February 2020.
  • Alenuihāhā Channel, HawaiiKai Lenny crossed it on swell alone in 2017, about 50 miles of riding.

Where it came from

In the late 1990s Laird Hamilton, Rush Randle, Dave Kalama and the Maui tow crew cut the seat off Air Chair water-ski foils, fitted footstraps (snowboard boots and bindings came later) and towed into waves; Mike Murphy at Air Chair supplied the foils. The 2003 film Step Into Liquid showed it to a wide audience. Paddle-in surf foiling arrived in the mid-2010s, when Maui's Alex Aguera reshaped thin kite-foil wings into thicker, high-lift sections that fly at the low speeds a surfer can paddle or a small swell can give.

More disciplines

Sources

  1. [1]

    US3747138A – Hydrofoil surfboards

    Google Patents (USPTO record), 1973-07-24 · tier 1 · patent

  2. [2]

    Adventures in Water Skiing, Hydrofoiling: Stand Up Guys, Air Board / Foil Board

    A Water Skier's Life (Tony Klarich) · tier 2 · article

  3. [3]

    US7144285B1 – Hydrofoil surfing board

    Google Patents (USPTO record), 2006-12-05 · tier 1 · patent

  4. [4]
  5. [5]

    Laird Flies At Massive Nazaré

    World Surf League, 2020-02-18 · tier 2 · article

  6. [6]

    Foilboard

    Wikipedia · tier 4 · reference

  7. [7]

    Tech talk: Sizing surf foil board

    Appletree Surfboards · tier 3 · manufacturer

  8. [8]

    Armstrong Surf Foil Board

    The Foiling Collective (retailer) · tier 3 · manufacturer

  9. [9]