I’m a firm believer in Murphy’s laws. When towing anything I always have at least one set of bearings, already greased, a good jack, the correct sized trailer lug nut wrench with extra lug nuts and the tools required to change a wheel bearing along side of the road. (Also a good properly inflated spare tire.) I’ve never had to actually do it along side the road myself but have assisted several others who found themselves in that very same predicament.
A policy of prevention means inspect and repack those bearing every season.
I’m a firm (somewhat anal) believer that if you maintain your bearings every season and you’re prepared to deal with a bearing failure on the road it will never happen.
Also, take a good hard look at your trailer tires and suspension. Dry rotted or tires over ten years old should be replaced regardless of tread depth. Seized spring shackle bolts can prevent the springs from flexing and puts a lot of shock load on tires, the trailer frame and your boat.
Tom G