Is it normal on Saturday to be out running just perfect and today went to Grand Haven and fouled a plug and just trolled all day.

How often is norm to foul a plug ?

What kind of engine? With todays high energy ignitions it is rare to foul plugs.

You should carry a new set or two sets if your running twins it is best to make a care package of things

Brad it's a 454 mag mpi 385 horse I last got fuel while I had it on the trailer and I never run 87 oct but I filled my truck up and just started fillin up the boat pulled out and realized I put in 87 and the next day I am fouling plugs.

87 should burn cleaner. I don't think thats the issue.

It could be a bad plug, bad wire or crud on the inside of the dist cap if its just one plug.