AT 450-SR 12
12–14ft (3.7–4.3m) boats
Single axle boat trailer with 12 multi-roller system to suit boats around 12 to 14 foot (3.7 to 4.3m). Designed for easy launch and retrieval of your boat.
From$3,365incl. GST
Size Guide
Boat Trailers for Mid-Size Boats (14-17ft)
Stepping up to a bigger boat means stepping up your trailer. Multi-roller systems, heavier chassis, and upgraded winches for boats in the 4.5 to 5.5 metre range.
The mid-size sweet spot
Trailers for 14 to 17 foot boats
Mid-size boats in the 14-17ft range are the workhorses of New Zealand boating. This is where you find the popular Stabicraft 1600 and 1700 models, Surtees 5.0 and 5.5, McLay 501 and 521, Fyran 500 series, Senator 500, and Ramco 500. These boats are big enough for serious inshore and harbour fishing but still practical to tow and launch with a standard ute or SUV.
At this size, the boat, motor, fuel, and gear typically push the total weight past the 750kg threshold, so brakes become a consideration. The trailer chassis also needs to step up: the AT 500-SR uses a heavier 70x50x4mm chassis compared to the 3mm gauge on smaller models, and the winch moves to a 5:1 ratio Trojan with 3,500kg-rated synthetic rope.
All mid-size trailers use multi-roller systems rather than carpet pads. At this weight, rollers make a real difference when launching and retrieving. The boat rolls on and off the trailer under its own weight rather than needing to be pushed and pulled across bunks, which matters when you are solo launching at a tidal ramp.
Mid-Size Boat Trailers
Trailers for boats 14-17ft (4.5-5.5m)
Single axle trailers with multi-roller systems, upgraded chassis, and heavier-duty winches. All fully hot-dip galvanised with LED submersible lights and bearing buddies as standard.
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AT 450-SR 16
12–14ft (3.7–4.3m) boats
Single axle boat trailer with 16 multi-roller system to suit boats around 12 to 14 foot (3.7 to 4.3m). The 16-roller setup suits wider hulls and heavier small boats.
From$3,570incl. GST
AT 500-SR
14–16ft (4.3–4.9m) boats
Single axle boat trailer with 16 multi-roller system to suit boats around 14 to 16 foot (4.3 to 4.9m). Heavier chassis and upgraded winch for mid-size hulls.
From$4,270incl. GST
AT 550-SR
15–17ft (4.6–5.2m) boats
Single axle boat trailer with 20 multi-roller system to suit boats around 15 to 17 foot (4.6 to 5.2m). Heavy-duty spec with upgraded tyres and winch.
From$4,975incl. GST
Choosing the right trailer
How to pick a trailer for your mid-size boat
When you need brakes
New Zealand law requires trailer brakes when the gross vehicle mass exceeds 750kg. Most mid-size boat and trailer combinations will exceed this. A 16ft aluminium boat with a 75hp outboard, fuel, and gear can easily weigh 900-1,200kg on the trailer. Alpha Trailers offers cable brakes ($950) as an add-on for any single-axle model, and hydraulic disc brakes ($1,450) for those who want the best stopping power. The investment is worth it for safety and legal compliance.
Roller systems for easier launching
At mid-size weights, rollers are not just a convenience but a practical necessity for many boaters. Trying to drag a 500kg+ hull across carpet pads at a shallow ramp is hard work. The 16 and 20-roller configurations on mid-size Alpha trailers let the boat roll back smoothly during launching and self-centre on the keel rollers during retrieval. This is especially valuable if you often launch solo or use ramps where the water level changes with the tide.
Matching popular NZ boat brands
The AT 500-SR and AT 550-SR are configured to suit the hull shapes of popular New Zealand boat brands including Stabicraft, Surtees, McLay, Fyran, Senator, Marco, Ramco, and Buccaneer. Every Alpha trailer is fully adjustable: the winch post, roller positions, and axle can all be set to match your specific hull shape. When you order, tell Alpha Trailers your boat make and model and they will configure the trailer before delivery.
Chassis and component upgrades at this size
Mid-size trailers step up from 3mm to 4mm wall thickness on the chassis, giving significantly more structural rigidity for heavier boats. The winch also upgrades from a 3:1 to a 5:1 ratio, making it easier to winch heavier boats up the skids. Tyres move to 165 R13 on the smaller mid-size models and 185 R14 on the AT 550-SR, each rated for the higher loads these trailers carry.
Frequently asked questions
What trailer do I need for a 5m boat?
A 5m (16ft) boat typically suits the AT 500-SR or AT 550-SR depending on hull weight and type. The AT 500-SR handles boats up to about 4.9m with its 16 multi-roller system and 1,250kg GVM. For heavier 5m boats or those closer to 5.2m, the AT 550-SR with its 20 multi-roller system and 1,500kg GVM provides more capacity. Contact Alpha Trailers with your boat details for a specific recommendation.
Do I need brakes on a trailer for a 16 foot boat?
Most 16ft boat and trailer combinations will exceed the 750kg GVM threshold where brakes are required by New Zealand law. A typical 16ft aluminium boat with a 60-90hp outboard and basic gear will weigh 800-1,200kg on the trailer. Alpha Trailers offers cable brakes ($950) and hydraulic disc brakes ($1,450) as upgrades on single-axle models. It is best to weigh your boat fully loaded to confirm.
What is the difference between 12 and 16 roller systems?
The number of rollers affects how well the boat is supported during launching and retrieval. A 12-roller system suits lighter, narrower hulls where the keel and lower hull need support. A 16-roller system spreads the load across more contact points, which is better for wider hulls and heavier boats. For mid-size boats, the 16 or 20-roller configurations provide smoother launching and better hull support.
Which trailer suits a Stabicraft or Surtees around 5m?
Stabicraft and Surtees boats in the 4.5-5.5m range are popular mid-size aluminium hulls. The AT 500-SR and AT 550-SR are both well suited, with the choice depending on boat weight and hull length. These models have heavier-gauge chassis (70x50x4mm) and upgraded Trojan 5:1 winches to handle the weight of these solidly built aluminium boats. Alpha Trailers can configure the roller positions to match your specific hull shape.
What tow vehicle do I need for a mid-size boat trailer?
A mid-size boat on an Alpha trailer will have a gross combined weight of roughly 1,000-1,800kg. Most modern mid-size SUVs, utes, and wagons can handle this. Check your vehicle's braked towing capacity in the owner's manual. As a rough guide, a Toyota Hilux, Ford Ranger, Mitsubishi Triton, or similar ute will comfortably tow any mid-size boat trailer in this range.
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