I agree very much with what has been said on this thread.. there are lots of variables… under inflated, overloaded, axle out of alignment, trailer load out of balance will cause the trailer to be squirrely and cause wear and heat issues. Maybe you drive everywhere at 90 mph?
Something is going on causing those tires to go. What kind of boat/how much weight is on this trailer?
It might not be unreasonable to switch up to a tandem axle trailer if some of the other things listed arent a factor.
Does the trailer have brakes? maybe a malfuntioning brakes are causing abnormal issues.
Al I know is a triler regularly blowing out tires is a serious hazard… to your eqipment, yourself, and other drivers.