SEAL 2025

I’m fully aware that for many people it’s a difficult idea to even consider sail sizes beyond 5.0 in waves, and that a 5.7 generally raises eyebrows. But when the wind stays below 18 knots for long periods, while the ocean refuses to calm down and continues to deliver at least two meters of swell – if not more – you have to accept compromises… or stay home and take up knitting. 

That’s how it is for me. Here in Sal, where I live, the coast facing Africa often offers conditions in spring and late summer that sit somewhere in between – conditions that, with the right equipment, can turn into something wonderful. 

From late April to the end of June, when the winter fun on the northwest spots comes to an end, you can rack up an endless series of sessions at Kite Beach (home of the cousins with bags and pumps…) that are great for both jumping and wave riding. Of course, you can forget about side- or side-off winds, small sails, and long groundswell lines that have travelled thousands of kilometers before hitting a rocky coast… Here, the conditions are more like European side-on, often side, but with 90/100-liter waveboards and sails between 5.2 and 5.9 – again, wave sails – it can be a lot of fun. 

The holiday atmosphere on land can be deceiving: the long, bright sandy beach and the center run by Mitu and Djo with a restaurant and other comforts create a dreamlike backdrop, but the spot itself is what I really care about. It’s a bit like Barbados… same walls, same water quality, and beautiful waves for both riding and jumping. 

All you need is large, early-planing wave gear. Since I needed to buy a new 5.7 and had just cleared out all my old equipment, I chose the 5.7 Seal from GunSails. I went for it because only a few brands still offer this size that can be rigged on a 400 mast (lately there’s been a slight trend toward longer masts…). As an old, tired guy, I’m not a fan of this trend — it shakes up just about all the certainties I’ve had in recent years. 

When I rolled the sail out on the beach for the first time (and then spent ten minutes chasing the tissue paper from the packaging blowing all over the place…), the Seal immediately came across as extremely well made, with perfect stitching, great reinforcements, and modern materials — which, in 2025, is honestly not something you can take for granted. The development of new materials has made it possible to place reinforcements only where needed, without making the sail unnecessarily heavy (also far from a given — I’ve had the chance to test many products from many other brands!). 

The result is a very light four-batten sail; this lightness is immediately noticeable on the beach, and it’s confirmed on the water thanks to its modern design. The large Dacron panel along the mast sleeve gives the sail incredible softness, the mast curve is almost perfect, and the batten rotation — even though the battens press against the mast to create more profile — is simply amazing, almost as if the battens weren’t there at all. 

The sail rigs on a 400 mast with 29 cm extension. While searching for the perfect trim, I noticed that the trimming range at both downhaul and outhaul is very small: around 3 cm between minimum and maximum downhaul and no more than 5 cm at the outhaul. You really have to be careful, as the tuning is extremely sensitive. I honestly didn’t pay attention to the FRED marking at the top of the sail — I relied entirely on my own experience. 

For the first session, I used one of the two masts recommended by GunSails, the Expert 400/19 RDM, a 70% carbon mast. The catalog also lists the Select 400/19, also RDM and 100% carbon, which is about 150 grams lighter — 1.59 kg compared to 1.75 kg for the Expert. For the second outing, I used a 100% carbon Ezzy RDM, also Constant Curve — and this setup gave me clearly better results than the combo from the first session. 

Despite its size, the Seal is a wave sail designed more for side-oriented conditions: riders looking for strong low-end power for European conditions or for heavier sailors may want to look toward a more powerful sail, such as the Horizon (if staying within GunSails) or even the Torro, both of which deliver a bit more grunt at the bottom end. 

The Seal is made to surf even in light wind — but with a wave that helps generate speed. On the water, it offers a super-soft feel both when going upwind and when wave riding: the lightness is especially noticeable in the wave, almost as if the sail were half a square meter smaller. 

If the wind occasionally drops below a certain threshold while the waves stay good, you do notice the lack of low-end power a bit — but with a few pumps the board gets going again quickly. 

All in all, it’s an excellent modern sail: superbly built, top-quality materials, great details, good design, and as usual at an unbeatable price (the Seal 5.7 is currently on sale at GunSails for 499 euros). 

The only criticisms I would mention are… the very limited — if not nearly nonexistent — color options, and the slight lack of punch in absolute low-end. I think I’ll try a few different masts to see if I can squeeze out a bit more. 

Before I wrap up this review, and to soften my earlier comment on the color options: there’s also the Re-Seal, with its green look, made from polyester film that consists — depending on the size — of up to 75% recycled PET bottles. Design, characteristics, and performance of the Re-Seal are identical to the regular Seal, but my friend Smink, who has been using a set for a while, has told me a lot of positive things… in his opinion, the Re-Seal has a little more to offer — both in feel and durability! 

Either way: the Seal passed the test — effortlessly and with good marks! 

Strengths: 
true wave sail, excellent value for money, high-quality construction, 
controlled/stable, soft feeling, neutrality while surfing, 
precise and highly maneuverable in the wave 

Weaknesses: 
limited power in the lower wind range 

Tested size: 428 cm 
Actual trim: 400 + 28 cm (+/– 2 cm) 
Boom length: 176 cm 
Weight: 3.7 kg 
Ideal mast: Expert/Select 400/19 RDM 
Compatible mast: Carbon RDM 400/19 
Tested mast: Expert 400/19 RDM 
Battens: 4 + 3 mini-battens 
Top: fixed 

Smooth Power Delivery 
With a new outline and a boom length shortened by 4 cm, the Seal / Re Seal (It consists of up to 75% recycled polyester film) 2025 has been revised, and features additional reinforcements at the clew and within the body of the profile. Two mini battens on the leech complete the setup. 
 
ON THE WATER 
Slightly less light than some of the other sails in this competitive test group – but by no means heavy – the new Seal delivers a smooth and controllable power, enhanced by the Dacron mast panel. The sail feels well balanced on both hands, making it easy to get planing in onshore conditions, generate clean forward drive, and quickly return upwind. 
Compared to others, the Seal comes across as more composed – both in acceleration and in three-dimensional movement. This results in a more controlled, confidence-inspiring riding style, whether in waves or strong wind, supported by a stable profile and reduced back-hand pressure. 
In surf, the sail’s good balance and noticeable softness tame the handling and reduce load spikes – perfect for smooth, flowing turns. The sail’s neutrality can be easily fine-tuned via back-hand pressure, depending on conditions and rider weight – and even with moderate tuning, it delivers a wide wind range. 
While it may not offer the same level of ultra-reactive lightness as some competitors, the even power distribution and calm behavior in gusts and chop make the Seal a reliable all-rounder. 
 
VERDICT 
Slightly more neutral on the back hand and more maneuverable overall, the Seal 2025 gains additional stability. A true plug-and-play sail with strong glide performance and well-balanced power – suitable for everything from hardcore wave to bump & jump, all at a very attractive price. 
 
PROS: 
• Price 
• Wide wind range 
• Great mix of stability and maneuverability 
• High comfort level 
• Well-balanced power vs. neutrality 

CONS: 
• Slightly less light and reactive for lighter riders 

The boom dimensions have been shortened by around four centimetres compared to the previous model to give the sail more agility, and the leech is now stabilized by two mini battens between the two upper battens. The manufacturer also claims to have made adjustments to the mast sleeve material and clew reinforcement as well as the mast protector and seams to make these stress areas more robust. Rigging the Seal correctly is extremely easy - the trim mark in the top helps you to find the right setup. The other features are also well done, the protector is long enough and can be folded easily. The Seal also generates its propulsion from a wide cut mast pocket. Due to the slightly shorter boom, the 2025 model is not quite as powerful as its predecessor when planing passively, but the sail is still one of the best planers in the group. Thankfully, you don't have to worry too much about the right trim: Simply adjust the luff tension according to the trim mark and pull the boom only moderately - rigged like this, the sail has a wide wind range. On the other hand, the concept benefits from the design changes in the form of improved handling: the Seal is balanced and very stable in the hands, it ignores strong gusts with stoic composure without the pressure point starting to move. In maneuvers, for example when jibing or rotating the sail, the new Seal is clearly more agile and playful than in the last test. The same applies to jumps and loop maneuvers. When riding waves, the Seal scores with a powerful but well-balanced characteristic: it offers good drive to arrive at the cutback with enough speed even in low-pressure waves or little wind, but also shines in powerful side-offshore waves with decent neutrality. 

SURF CONCLUSION The 2025 Seal turns out to be much more balanced and playful, making it more suitable for demanding wave surfers. Nevertheless, thanks to its good planing performance, great control and pleasingly low trim sensitivity, it remains a tip as a strong wind sail for flat water. 

The Verdict: The power and precision control of the SEAL will reward the rider with a playful, reactive rig that thrives on manoeuvre orientated sailing. Capable of adapting to small and large waves, the SEAL when powered, gives the rider confidence to play and ride; all for an incredibly attractive price point.

The Lowdown: The SEAL is GUNSAILS' dedicated wave sail, branded as their Core Wave Sail. Designed to be paired with either a 370 or 400 mast and tensioned to the brands FRED downhaul mark, the SEAL immediately ticks all the boxes for a wave sail with its high, angular foot and distinctly angular outline. Its clean, streamlined appearance catches the eye even before delving into the finer details of its construction and technology. The SEAL is available in two options: Gun Sails' RE-SEAL construction, which incorporates recycled materials, or the regular version which has a striking colourway featuring shades of red with vibrant blue detailing—the version we received for testing.

Two standout features define the SEAL upon closer examination. First, a double mini-batten in the top panel reduces flutter, enhances leech stability, and improves the sail’s overall efficiency. Second, the SEAL features an impressive Dacron luff panel that spans the bottom three panels, starting at the tack. This panel provides power on demand with a touch of softness, allowing the sail to adapt smoothly and deliver responsive on/off power while riding. The SEAL is constructed using multiple grades of X-Ply, strategically placed throughout the sail. Thicker, more robust X-Ply is used in areas of high stress and load, while thinner, lighter X-Ply is incorporated in sections like the top of the sail to reduce swing weight without compromising durability. This deliberate and targeted design enhances both the performance and structural integrity of the sail. The SEAL not only looks the part but also features an uncomplicated yet effective technological makeup that delivers exceptional performance—all at an incredibly attractive price point that’s hard to ignore.

Performance: Immediately upon stepping on the board with the SEAL in hand, it feels smaller than its quoted size. Its narrow boom, angular foot, and overall outline combine to create this impression. For most riders, this will likely encourage a more radical style of riding, as the SEAL invites you to throw it around during manoeuvres on a wave. Preferring ample power to get you up and going, the SEAL delivers with a balanced combination of firmness and softness, thanks to the Dacron luff panel, which absorbs some sting and smoothens the firm power delivery. When powered, the SEAL feels at its best in the rider's hands—stable, neutral, and incredibly reactive to adjustments. On a wave, the SEAL maintains a neutral power profile, allowing full commitment to manoeuvres. Its compact outline and nimble feel make transitions quick and seamless, enabling smooth shifts from bottom turns to sharp, slashy top turns in the blink of an eye. The SEAL demonstrates that it doesn’t require big waves to facilitate big, powerful manoeuvres. It shines even on smaller waves, where tighter, faster manoeuvres are necessary. The SEAL rewards the rider with an impressive mix of stability and agility. Its smaller feel in hand, reactive nature, and overall ease of manoeuvrability makes the SEAL an excellent choice for riders who embrace a proactive riding style and aren’t afraid to push the rig to its limits.

Direct and Discreet

GUNSAILS updates its sails with improved materials: a more durable, water-repellent mast sleeve, reinforced foot panel, upgraded mast foot protector, and wider seams in high-stress zones. The Seal features a new outline, now 4 cm more compact at the clew, along with solid reinforcements and new mini battens in the top section.

ON THE WATER

Always listening to user feedback, Gunsails designers focus on sails that are easy to rig and fine-tune. Just follow the instructions, add a bit of downhaul tension – and the Seal is perfectly trimmed.

The 4.5 version delivers a lively start and sets up with a relatively firm profile on a 370 mast. Acceleration is sharp and direct over short distances, with a rig that feels reactive and crisp, yet still easy to manage.

The Seal offers excellent freedom of movement, allowing you to position the sail exactly where you want it. Weight and size are in the mid-range, with the more compact design clearly noticeable compared to the previous version.

In wave riding, the Seal becomes neutral in an instant – ideal for drawing smooth arcs, tightening your turns, or going full radical. Thanks to its stiffness and discreet nature, it allows maximum freedom of motion, though it doesn't provide the same rebound or "juice" out of the turn as softer sails might.

VERDICT

With a shorter boom and a dry, direct handling feel, the Seal 4.5 is agile and ready to go head-to-head with the most surf-oriented wave sails. It’s aimed at wave riders who focus on carving clean lines and want solid surf performance without breaking the bank.

Pros:

• Dynamic handling
• Great freedom of movement
• Strong neutrality in wave riding
• No constraints – full control

Cons:

• Less drive when exiting turns