What can cause a tire blowout on a boat trailer?

Tire blowouts on boat trailers are rarely caused by a defective tire. Instead, they’re usually the result of operating conditions that can be prevented with proper maintenance. The three main culprits are:

Overloaded Tires

• Every trailer tire is built with a maximum load rating, which depends on proper inflation. If you exceed this limit, the tire is forced to carry more weight than it was designed for.
• On boat trailers, this often happens when owners underestimate the combined weight of the boat, fuel, gear, water, and trailer itself.
  Example: Filling livewells or leaving heavy gear onboard can push your trailer load past its rated capacity without realizing it.
• Prevention: Know your trailer’s Gross Vehicle Weight Rating (GVWR) and check against the tire’s load rating on the sidewall. Weigh your loaded trailer at a certified scale if in doubt.

Incorrect Inflation (Underinflated or Overinflated)

• Underinflation: The most common blowout cause. It creates excess sidewall flex, generating heat. Boat trailers often face long highway drives, so heat buildup is accelerated. When that hot tire is then submerged at a boat ramp, the rapid cooling can stress the carcass even more. Underinflated tires also wear on the edges.
• Overinflation: Leads to reduced ground contact and faster center tread wear. On wet launch ramps, overinflated tires may also provide less traction.
• Prevention: Always inflate to the maximum cold PSI shown on the tire sidewall (or the tire manufacturer’s official chart). This ensures the tire is operating at its rated load capacity. Check pressure before every trip, as even a few PSI loss matters on trailers.

Improper Weight Distribution

• Boat trailers rely on balanced load across axles and proper tongue weight (about 7-10% of total weight on the hitch).
• If the boat is loaded too far forward or aft, or if gear is unevenly stowed, one set of tires may carry more weight than the others. This overloads individual tires and increases the risk of blowouts.
• Prevention: Ensure the boat sits evenly on bunks or rollers. Store heavy items (anchors, coolers, batteries) so weight is distributed evenly. Adjust bow stop and winch position if tongue weight is too light or too heavy.

Extra Boat Trailer Considerations

• Saltwater Exposure: Corrosion around bead seats and valve stems can lead to air loss, making underinflation more likely. Always rinse your trailer wheels and tires with fresh water after saltwater use.
• Long Highway Trips: Boat trailers often log hundreds of highway miles in one haul. This means sustained heat buildup, which magnifies the effects of improper inflation and overloading compared to short city drives.
• Storage Issues: Tires left underinflated during long storage periods can develop internal cracks or flat spots, making them more vulnerable to blowouts when put back in service.