I'm not an expert on this, but my dad has kept a boat in both Havelock and New Bern. New Bern is closer and would be about 2 hrs 15 min from Apex, maybe less from Clayton. If you Google "Marina New Bern" you'll find several options, and many have their rates on line. Here is an example of rates:
Northwest Creek Marina
When there have been threatened hurricanes my dad has generally gone and anchored his boat in the middle of the creek, as do most of the people in the marina.