It's not the beam you have to worry about in the ICW, it's the bridges and the most important thing, your draft
. A cat should have no problems. If you have the time and don't mind motoring do the ICW. If you do jaunts outside it might take the same amount of time, going out into the ocean and back into a port wastes a lot of time. I have not tried this but it might be possible to do day trips up the coast but the winds have to be favourable because looking for an anchorage in unfamiliar waters at night is not advisable. Brunswick to Charleston should take less than 30 hours. In this stretch it's either ICW or the Atlantic Ocean
. For a newbie the ICW is very interesting. If in a hurry go in one shot.