The ST21 is the specialist's double: a dedicated two-person hull with racing heritage and the highest load rating in the Stellar touring family. As an authorized agent and carbon fiber kayak manufacturer, we quote per laminate and per customization level - send your crew profile for FOB terms.
OEM / ODM Production Available
Dedicated 2-Person Tandem Hull
ISO 9001 Certified Factory
Authorized Stellar Agent (Asia & South America)
Custom Carbon Fiber Kayak Manufacturer
The ST21: Synchronized Performance for Two - Racing Heritage, Touring Range
A tandem kayak is fast only when the hull, the cockpits and the steering all agree on one thing: two paddlers pulling as one. The ST21 is engineered around that idea - a long, narrow waterline that cuts through chop, a standard over-stern rudder that keeps a 6.5-meter boat on line, and 260 kg of rated capacity for two paddlers and expedition load.
COCKPIT 1 + COCKPIT 2HATCH6.5 m - 3 bulkheads · 177 L sealed storage · over-stern rudderSide profile placeholder - replace with ST21 hull photo
Two paddlers change everything about hull design. Power arrives in alternating pulses instead of a steady stroke, weight sits at two points instead of one, and the boat must hold a line through wind and following seas that would barely touch a solo hull. Stellar answers with the longest waterline in the touring family - 21'4" - kept deliberately narrow at 56.8 cm so the extra length translates into speed instead of sluggishness.
That speed DNA is why the ST21 is described the way it is: a hull that "cuts through the water," equally at home in a race start line and on a multi-day tour where you want to eat up the miles. A full three-point footbrace gives both paddlers a stable platform for powerful leg drive, and the over-stern rudder - standard, not an option - handles the steering load so the crew can keep pulling.
We build the ST21 in our own factory under Stellar license and under your brand. For teams, outfitters and importers, that means a custom carbon fiber kayak program where the tandem hull, the color system and the fleet mix are all part of one order.
21'4"
Longest hull in the Stellar touring family - maximum waterline speed
260 kg
Highest load rating in the family - two adults plus expedition gear
Rudder
Over-stern rudder standard - steering built in, not bolted on later
177 L
72 L bow + 105 L stern sealed storage across 3 bulkheads
Tandem Engineering
What Makes a Two-Person Kayak Actually Fast - Station by Station
Read the ST21 from bow to stern and every station earns its place in the crew's performance: the waterline that carries two strokes, the cockpits that place two bodies in balance, and the rudder that lets both paddlers keep pulling.
BOW HATCH 72LSEALED BULKHEADS ×32 COCKPITS · 31.9" × 17.3" EACHSTERN 105 LOVER-STERN RUDDERAnnotated side profile placeholder - replace with factory line drawing
WATERLINE
Long + narrow = fast. At 21'4" the ST21 carries the family's longest waterline, and at 56.8 cm its beam matches the much shorter S16 G3 - the length buys speed, the narrowness keeps the boat from feeling like a barge.
01
DUAL COCKPITS
Two bodies, one balance point. Cockpits are placed to split the 260 kg rating across the hull's trim, with molded seat pads and thigh braces holding both paddlers securely in rough water.
02
3-POINT FOOTBRACE
Leg drive for both crews. A full three-point touring footbrace gives each paddler an independent, adjustable platform - powerful strokes from the front seat, powerful strokes from the back.
03
RUDDER SYSTEM
Steering that never steals a stroke. The over-stern rudder is factory-standard, deploying when wind and current demand it and retracting for a clean, fast hull when conditions are calm.
04
Specifications
Stellar ST21 - Technical Data
|
Length |
21'4" / 6.5 m |
|
Beam |
22.4" / 56.8 cm |
|
Depth |
13.7" / 34.8 cm |
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Paddler Height Range |
5' – 6'6" / 1.5 – 2.0 m |
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Max Load |
575 lbs / 260 kg (two paddlers + gear) |
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Cockpit Dimensions |
31.9" L × 17.3" W (81 × 44 cm) - two cockpits |
|
Bow Storage |
19 gal / 72 L |
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Stern Storage |
27.7 gal / 105 L |
|
Total Sealed Storage |
177 L · 3 bulkheads · 2 storage hatches |
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Steering System |
Over-stern rudder (standard) |
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Footbrace |
QR Touring footbrace - full three-point, adjustable per cockpit |
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Seat & Support |
Bottle-holder seat pad · molded seat & thigh braces |
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Available Layups |
Alpha · Excel · Multi-Sport · Advantage |
Why a rudder, not just a skeg
- On a 6.5 m tandem, windage is twice the surface area - a retractable skeg alone can't hold a loaded double on line
- The over-stern rudder deploys only when needed; calm-water paddling keeps a clean hull for speed
- Pedals sit within reach of both cockpits, so the steering load never forces a crew to stop pulling
- Rudder hardware is part of the factory spec, not an aftermarket retrofit
Who orders the ST21 in bulk
Coastal touring schools running two-paddler courses; outfitters offering guided double expeditions; racing clubs that train in matched pairs; importers launching a dedicated tandem line. Tell us your crew profile - we build the fleet to match.
Four Laminates on a Tandem Hull - Where Does Your Program Sit?
Every kilogram saved on a 6.5 m double means two people lifting less at the car roof, but a rental tandem also takes twice the abuse. The quadrant below maps stiffness against toughness so you can pick the schedule that fits your crew's mission.
Alpha - the race crew's choice
Woven Toray 3k carbon over Nomex® honeycomb, clear-coated and heat-cured. At 23 kg it saves over 3 kg vs the toughest build - the difference between two people struggling and two people lifting with room to spare. For matched pairs chasing pace, stiffness is everything.
Excel - stiffness, lightened budget
Heat-cured epoxy Kevlar® and glass over Nomex® honeycomb at the same 23 kg. Nearly the Alpha's performance for a noticeably lower cost per hull - the volume pick for clubs that want a fast double without the premium build.
Multi-Sport - the all-water double
Single-layer carbon & Kevlar® hull with an Advantage deck, rated to shrug off Class I–II current and shallow-water contact. The rare tandem that survives a river trip and a rocky landing - and it ships with the rudder as standard.
Advantage - the rental workhorse
Infused epoxy glass with Soric® core at 26 kg: the puncture-resistant, lowest-repair-cost build, matched to a 260 kg load rating that rental doubles hit every single day.
FAQ
Q: How is the ST21 different from the ST19 converted to tandem mode?
A: The ST19 is a modular boat that becomes a tandem by bolting on a second cockpit section - flexibility is its whole point. The ST21 is a dedicated two-person hull, purpose-built around tandem performance: a longer waterline (21'4" vs 19'), a narrower speed-first beam, racing heritage and an over-stern rudder as standard equipment. If your program runs doubles all season and speed matters, the ST21 is the specialist; the ST19 is the versatile answer. Many fleets carry both.
Q: Our two paddlers are very different heights - can both be comfortable?
A: Yes. Each cockpit has its own adjustable three-point footbrace and seat trim, so the front and back paddler set up independently. Under our OEM service we also offer Crew Fit Mapping: we set both stations to your specific crew profile before series build, or standardize a universal fit for rental fleets that see many different pairs.
Q: Why does the ST21 use a rudder instead of just a skeg?
A: At 6.5 meters with two paddlers and gear, a loaded double has a lot of windage and momentum. A retractable skeg helps tracking but can't actively hold a line in crosswind and following seas. The over-stern rudder steers actively, deploys only when needed, and retracts to keep the hull clean for speed in calm conditions. It is factory-standard on this hull - not an aftermarket retrofit.
Q: Is the 260 kg rating really necessary on a two-person kayak?
A: It is the highest rating in the Stellar touring family, and it exists because a touring double carries two adults plus multi-day gear - paddlers, water, food, camping equipment and safety gear all add up quickly. For outfitters it also means one boat legally covers guided two-person trips with full expedition load, which is why expedition-minded rental programs choose the ST21 over lighter doubles.
Q: Which laminate should a rental fleet choose for the ST21?
A: Most rental operators pick Advantage (26 kg): infused glass with Soric® core is puncture-resistant, carries the 260 kg rating with the lowest repair cost per season, and its price per hull fits fleet budgets. If your doubles see mixed water or rocky landings, Multi-Sport (25.5 kg) adds the Class I–II tolerance. Racing clubs that lift their own boats usually go Alpha or Excel at 23 kg. We can also build a mixed fleet - one laminate for the rental line, one for the club line - in a single container.
Q: Which B2B buyers typically order the ST21?
A: Four profiles dominate: coastal touring schools running two-paddler courses; outfitters offering guided double expeditions that need the 260 kg capacity; racing clubs that train matched pairs; and brand importers who want a dedicated tandem line under their own label. We quote per laminate and per customization level - send your crew profile and volume, and we come back with a fleet recommendation.
Hangzhou Chengxin Composite Material Co., Ltd. is one of the most reliable manufacturers and suppliers of racing-line carbon fiber double kayak in China. With a professional production team, we are able to meet the needs of the majority of our customers. Please rest assured to buy customized racing-line carbon fiber double kayak from our factory.
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