Galvanised vs Aluminium Boat Trailers
A galvanised boat trailer and an aluminium boat trailer both cope with saltwater launching, but they suit different boats and budgets. Sea Raider builds both: hot-dip galvanised steel trailers for boats from 4.3m to 5.7m, and aluminium trailers for boats up to around 8m. This guide compares weight, corrosion, price and upkeep so you can choose the right one. The full line-up is on the boat trailer range page.
The two ranges at a glance
| Galvanised steel | Aluminium | |
|---|---|---|
| Sea Raider models | 4.8m 750kg, 4.8m 1200kg, 5.7m 1400kg, 5.7m tandem 2000kg | 6.9m aluminium, 8.2m aluminium |
| Suits boats | 4.3m to 5.7m | Up to around 21ft (about 6.4m) on the 6.9m; up to around 8m on the 8.2m |
| Rating | ATM 750kg to 2000kg | 6.9m rated to 1550kg; 8.2m ATM 3,490kg |
| Axles | Single or tandem | Dual axle |
| Brakes | Mechanical override on the 1200kg, 1400kg and 2000kg models | Braked; hydraulic on the 8.2m |
| Price | From $2,195 to $4,974 | From $12,000 to $15,000 |
Weight
Aluminium is the lighter material, and on a large trailer that matters. The loaded boat plus the trailer’s tare has to stay inside the trailer’s ATM and inside the tow vehicle’s braked towing capacity. On a 7m or 8m plate boat, a lighter trailer can be the difference between staying under the vehicle’s limit and not. On a 4.8m or 5.7m boat the trailer’s weight is a small share of the total and the galvanised steel frame’s extra kilograms are not a problem for a normal tow vehicle.
Corrosion
Hot-dip galvanising coats the whole steel frame, inside and out, in zinc that corrodes slowly in place of the steel. The 4.8m and 5.7m frames are fully hot-dip galvanised, so they stand up to regular saltwater launching. Scratches and chips are where rust starts, so touch them up with cold galvanising paint. Aluminium does not rust, though it can pit or suffer white corrosion where dissimilar metals meet or where salt sits in crevices, so fastener points and the areas around steel fittings need rinsing and checking. Either material will last if it is washed down after a salt launch; neither will if it is left to dry salty.
Price
Galvanised steel is the lower-cost way to build a strong trailer, which is why the galvanised range starts at $2,195 and tops out at $4,974 for the 5.7m tandem. The aluminium trailers are bigger, dual-axle trailers for bigger boats and are priced from $12,000 to $15,000. For a boat up to 5.7m the galvanised trailer is the sensible buy; for a boat over about 6m the aluminium trailer is the one built for the job.
Maintenance after saltwater launching
- Rinse the whole trailer with fresh water after every salt launch, including inside the drawbar and chassis rails and around the springs, hubs and brake parts.
- Flush the mechanical override brakes on the galvanised 1200kg, 1400kg and 2000kg models and work the coupling so it does not seize.
- Check the LED lights and the 7-pin plug; connections corrode if left salty.
- On a galvanised trailer, touch up any chips with cold galvanising paint before rust gets under the coating.
- On an aluminium trailer, look at fastener points and anywhere steel fittings meet the frame for white corrosion, and keep them rinsed.
- Check roller and skid positions after the first few trips. The owner’s manual has a full trailer maintenance schedule.
Which Sea Raider boats go with which trailer
The galvanised range covers boats up to 5.7m – tinnies, runabouts and side consoles – and is the natural match for smaller aluminium and fibreglass hulls of any brand. The 6.9m aluminium trailer suits boats up to around 21ft (about 6.4m), which takes in the Sea Raider 6.25m range. The 8.2m aluminium trailer suits boats up to around 8m, which covers the 6.85m, 7.5m and Boss 770 class. Both aluminium trailers are custom-matched to the hull – see custom-built boat trailers. If you are unsure of the rating you need, the what size boat trailer do I need guide works through it.
Options, registration, delivery and finance
Every trailer in both ranges can be fitted with a D-Flector boat stone guard before it leaves the yard – see boat stone guards for sizes and prices. Queensland registration can be arranged on request (ask for a price), delivery is priced by state as transport from Brisbane on the registration and delivery page, and low-cost finance is available on trailer-only purchases – see boat trailer finance.
Frequently asked questions
Yes. The 4.8m and 5.7m trailers are fully hot-dip galvanised, which protects the steel frame inside and out. Rinse the trailer with fresh water after every salt launch and touch up chips with cold galvanising paint.
For a boat over about 6m, yes: the aluminium 6.9m and 8.2m trailers are built for larger, heavier hulls and keep the tare down. For a boat up to 5.7m a galvanised trailer does the job at a fraction of the price.
It does not rust, but it can pit or form white corrosion where salt sits in crevices or where steel fittings meet the frame. Rinsing after each launch and checking fastener points keeps it in check.
The 6.9m aluminium trailer suits boats up to around 21ft (about 6.4m), which covers the 6.25m range. The 6.85m, 7.5m and Boss 770 class go on the 8.2m aluminium trailer.
Sea Raider’s galvanised trailers are $2,195 to $4,974 and the aluminium trailers are $12,000 to $15,000, before options, registration and delivery.
Ready to choose?
Tell us your boat’s length, loaded weight and hull type and we will recommend galvanised or aluminium and quote the trailer. Enquire online or call the Sea Raider team at Cleveland Marina, Brisbane on 07 3477 9338.