Hydrofoil stabs

Most people know that both front and rear wings (or foils) fit onto the fuselage, and the rear wing is known by most as a tail wing or rear stabiliser.

So what do tail wings do? They counter the lifting force of the front wing in order to stabilise your flight. They also influence the speed and riding characteristics of your front wing. Changing your tail wing can dramatically change the performance, and to a degree, can alter the characteristics of a front wing. The easiest way of doing this is to change the size of your existing tail. Generally speaking using a smaller tail will increase your speed and allow you to turn more easily, but the payback is that it reduces your stability. Conversely, using a bigger tail will do the opposite.

HOWEVER, the design of your tail is every bit as important as it's size, perhaps even more so. There are many tail designs available: flat, curved down, curved up, swept back, winglets (up & down), deep chord, narrow chord, high aspect, low aspect, anhedral, dihedral, etc etc.

Thankfully GoFoil have done all the R&D to narrow this rather confusing array down to 2 designs that they feel suit their front wings best. A flat tail (18" either wide or narrow chord) and a design that has upturned winglets - what they call the flip-tip tail (17.5", 14.5" & 12.5"). Essentially, the flat tail is slightly faster, has great lift, and although it turns very well, it can have a skatey feel as there it provides less yaw control - whether this is good or bad depends entirely on the rider. The flip tip tail is still plenty fast and also has good lift, but is much more stable - both directionally and when turning. To me the flip tip feels much more grippy when carving (similar to the feeling when using the rails of a surfboard to turn), but I also love the feeling of efficiency and speed you get with the flat tail. Obviously the size of your tail matters.

Bigger tails give more lift, but produce more drag due to the increase in surface area cutting through the water. Most people would be best advised to match the size of your tail wing to the size of your front wing - big goes with big, small goes with small, BUT, here's where anyone can buck the trend. As you get more experienced a lot of people are finding that they prefer a smaller tail - it certainly loosens up a front foil and improves its turning capability, but the trade-off of course is a lack of stability. The good news here is that once you learn to deal with this (and anyone can given enough practice) it's not such an issue. If you are after speed, design is more important than size - a wide, thin, flat tail (high aspect) is best for speed.

My go-to tail wing is the 14.5" flip tip - it does everything well and is super predictable which means I can relax and enjoy my time on the water. If I want more speed I'll use a flat tail (I cut my 18W down to 14.5" and love it) and am thinking about getting the 12.5" flip-tip just to see what that brings to my game.

In order to change the length of your fuselage most companies require you to change the whole fuselage, but GoFoil have their own (very effective) way of doing this by using what they call a 'pedestal', which slots onto the end of the fuselage. The tail wing screws directly onto the pedestal. At the moment GoFoil have 2 pedestals, a long (9.5") and a short (6.5") version, which allow you to lengthen and shorten your fuselage very quickly and easily. Generally speaking a long pedestal is best for use with a wind wing as they are much more pitch stable when at speed, and a short fuselage is best for surfing as they turn much better, are more reactive to rider input, and require a faster pump frequency which helps when pumping back out to connect multiple waves.

Words by Dominic Hoskyns - resides in Oman

Check out our selection of Go foil Hydrofoils here