Its a little more than 50 miles but very easy and pleasant ride. From where you are staying you want to head east and catch the Greeneway like you were returning to the airport south entrance. Just stay on the Greeneway past the airport and you will come to the Beeline SR527 exit. Go east on that and it runs straight to the port. The only place you have to change direction is right after crossing the St Johns river where the Beeline forks. Watch for the roadsign overhead with the ship on it, stay right and it takes you to the port. You will pay a total of $3.25 in tolls, stopping at two toll booths on the Greeneway and one right after getting on the Beeline.