Boat Trailering: Complete Guide

Trailering a boat gives you the freedom to explore different lakes, rivers, and coastal areas without the cost of a marina berth. It also means you can store your boat at home, saving on annual mooring fees. This guide covers everything from choosing the right trailer to launching, retrieving, and maintaining your trailer.

Choosing the right trailer

The trailer must match your boat's size, weight, and hull shape. A mismatched trailer can damage the hull, make launching difficult, and create dangerous towing conditions.

Trailer types

• Bunk trailer: Two long wooden or carpeted bunks support the hull. Best for V-hull boats. Simple, durable, and affordable. The boat sits on the bunks and is winched on.
• Roller trailer: A series of rollers support and guide the boat. Easier launching and retrieval (the boat rolls on and off), but more maintenance (rollers wear out). Best for heavier boats or steep ramps.
• Float-on trailer: Designed to be partially submerged so the boat floats on and off. Common for larger boats and sailboats.
• Custom trailer: Built specifically for your boat's hull shape. Provides the best support but is the most expensive option.

Sizing the trailer

The trailer's capacity must exceed the total towed weight — the boat plus engine, fuel, gear, and any water in the bilge. As a rule of thumb, choose a trailer rated for at least 20 percent more than your boat's fully loaded weight.

Towing capacity and vehicle requirements

Your tow vehicle must have sufficient towing capacity for the loaded trailer. Check your vehicle's maximum towing weight in the owner's manual or manufacturer's website. Never exceed the rated capacity — doing so risks transmission failure, brake failure, and loss of control.

Key towing considerations:

• Tow ball weight: The downward force on the tow ball should be 5 to 10 percent of the total trailer weight. Too little causes sway; too much overloads the vehicle's rear suspension.
• Brakes: Trailers over 750 kg (varies by country) typically require overrun brakes. Trailers over 3,500 kg may require electric or hydraulic brakes.
• Mirrors: Extended towing mirrors are essential for visibility. In most countries, you must be able to see past both sides of the trailer.
• License requirements: Many countries require an additional license category for trailers over 750 kg. Check your local regulations.

Launching your boat

Launching is the moment many new trailer boaters find stressful. With preparation and practice, it becomes routine:

1. Prepare before reaching the ramp: Remove tie-down straps, load gear, install drain plug, attach a bow line. Do this in the staging area, not on the ramp.
2. Back down the ramp slowly: Use your mirrors. Have a spotter guide you. Stop when the trailer is deep enough — for bunk trailers, the rear bunks should be just submerged. For roller trailers, less depth is needed.
3. Release the winch: Unhook the bow strap. On a roller trailer, the boat may roll off — keep a bow line attached. On a bunk trailer, you may need to back further until the boat floats free.
4. Move the boat to the dock: Use the bow line to guide the boat to a temporary mooring spot. Do not block the ramp.
5. Park the vehicle and trailer: Drive to the designated parking area immediately. Do not leave your vehicle on the ramp.

Retrieving your boat

1. Approach the ramp: Wait your turn. Prepare the boat by removing gear and raising the outboard if applicable.
2. Back the trailer in: Same depth as launching. Have a spotter.
3. Drive or winch the boat on: On a roller trailer, idle the boat onto the trailer and hook the bow strap immediately. On a bunk trailer, you may need to winch the last few feet — do not power the boat onto bunks at speed.
4. Secure the boat: Attach the bow strap and winch tight. Pull the trailer out of the water.
5. Final checks: Away from the ramp, attach tie-down straps, raise the outboard, check the drain plug is removed, and inspect for any damage.

Trailer maintenance

Boat trailers live in a harsh environment — saltwater, road grime, and constant loading and unloading. Regular maintenance is essential:

• Hubs and bearings: Check bearing buddies (if fitted) for grease. Repack bearings annually or every 2,000 km. A failed bearing on the road is a major problem.
• Tyres: Check pressure before every trip. Trailer tyres age out before they wear out — replace every 5 to 7 years regardless of tread depth. Check for dry rot and sidewall cracking.
• Lights: Test all lights before every trip. Corrosion in light fittings is common — use dielectric grease on connections.
• Brakes: Flush brake assemblies with fresh water after every saltwater use. Inspect brake pads and cables annually.
• Frame: Rinse the entire trailer with fresh water after every use, especially after saltwater. Inspect for rust annually — treat and paint any corrosion immediately.
• Winch: Inspect the winch strap or cable for fraying. Replace at the first sign of wear — a snapped winch line under load is dangerous.

Legal requirements

Trailer regulations vary by country. Common requirements include:

• Registration: Most countries require trailers to be registered and display a license plate.
• Lights: Tail lights, brake lights, indicators, and reflectors are mandatory.
• Speed limits: Many countries impose lower speed limits for vehicles towing trailers — typically 80 km/h on motorways and 65 km/h on other roads, though this varies.
• Width limits: Boats wider than 2.55 m (EU) or 8.5 ft (US) may require special permits or escort vehicles.
• Weight limits: Exceeding the trailer's plated weight or the vehicle's towing capacity is illegal and invalidates insurance.

For more on boat ownership costs including trailering, see our boat maintenance costs guide. For boat trailers themselves, browse boat trailers for sale.