I was sailing my 19' O'Day Mariner to a island 7mi away for an overnighter. On the way there, the swells were fairly larger 3-5' we were running with the centerboard all the way down and when I went in the cockpit I noticed the centerboard housing was swaying when the boat rocked. I also noticed it the next day when the swells were much smaller and were were on a run. The housing was moving about 1-2" is is this a problem or is the fiberglass housing supposed to flex? We are planning another trip the the island and don't want to sink 4 miles out.