【Alkali Fins/アルカリフィン】The Big Sky High Aspect Twin

【Alkali Fins/アルカリフィン】The Big Sky High Aspect Twin

販売価格: 16,800円(税別)

(税込: 18,480円)


The Big Sky High Aspect Twinは、一般的なモダンツインよりも小さめのデザインだ。




The Big Sky High Aspect Twin is smaller than most modern twins. 

Andrew Kidman experimented a slightly larger version of this fin with Larry Gephart. Over the years, they continued to test and make the fin smaller, seeing what was possible before the fin became too small. The smaller the fin, the faster a surfer can go - but small fins will be harder to control. 

The centre foil helps control this speed and the cavitation caused by turning at high speeds.



“I don't see any point in having a single foiled twin fin, and that's just my opinion. They're fast, but they slip - I can't stand that feeling of slip when I'm trying to hold the board in the water at max speed through a carve. If you want to have smooth control, double foiled is the go. With these fins, you have more control and a smaller profile to keep the speed.” Andrew Kidman



Height / Depth = 135mm (5.3") 

Base = 140mm (5.5")

Futures Compatible


The Alkali x Big Sky Sunrise Collection 


Alkali フィンは、アンドリュー・キッドマン、それからBig Sky Limitedと再びタッグを組み、この度新たに3タイプのフィンを発表する。  





Twin KeelとHigh Aspect Twinは、どちらもセンターフォイル(50/50)に特徴がある。

センターフォイルでは、水中を進むとフィン両面を包むように水が流れる。Single Finと同じ仕組みだ。これがターン時のスリップを抑え操作性を与えてくれる。よりなめらかな乗り心地だ。


Featuring the unique colours of the Hawaiian Sunrise Shell.

Alkali is proud to be working once more with Andrew Kidman and Big Sky Limited with a collection of three different fins.

The collection brings together some of Andrew Kidman’s favourite fins, with a goal to continue testing and adjusting these fins along the way. Our aim is to progress the designs, and not become stagnant.

All Alkali fins are made in the traditional method - from fibreglass and resin panels.This means that you can sand out any damage that occurs from rocks and reef. 

We also encourage you to customise the fins to your liking; by foiling (*sanding) them down to a smaller size, making the tip thinner for more flex, or altering the outline. Don’t be afraid to experiment. 


Centre Foiled Design 

The Twin Keel and High Aspect Twin both feature a centre foil.

Basically, this allows the water to wrap around the fin as the fin travels through the water, the same way it does with a  Single Fin. This gives the surfer more control and stops the fin from breaking free (cavitating) in the turn. It's a smoother feeling.