Good info above by Judyann. Remember any screened in port will collect salt spray, sand, pollen etc. They have to be cleaned daily. They cut way down on the breeze. And won't keep out no-see-ums. So what you might want to do instead is have a breeze on you and try the coils. But at the end of the day, the repellant is your best bet. Or try walking out to the end of the pier.