Amanita, 2 yrs.ago we had to fly into Mobay and made it to Porti, via private taxi, in 3.5 hrs. I'm estimating 2 - 2.5 hrs. via public transport from Ochi to Port Antonio. 3 maximum, so it could be done in a day. If you start early you'll usually go a bit faster unless you're on a school bus route
It used to be:
Ochi to Port Maria via minibus; starting at the Ochi central terminal area.
Port Maria to Annato Bay via route taxi
Annatto Bay to Porti via bus, minivan or (not recommended) "fast car"/shared taxi. (Far too manic in the driving.) I haven't done this in a few years but the route and system is the same.
From Port Antonio to Zion Country you can take a Manchioneal minivan from behind the Texaco on Harbour St. Route taxis may or may not be faster. You take a route taxi to Long Bay, change at the east end of Long Bay and wait for a Manchionel route taxi. Last Spring I'd have saved some time, in the long run, by taking the minivan when going to Zion Co. On the way back I picked up a route taxi that went all the way into Port Antonio. By public transport it will take an hour or less.
Get off at Long Road in Muirton Pen and walk a few minutes up Long Road.. And if you'e staying overnight at Zion Co. check to see if it happens to be a day that Free-I is travelling into Port Antonio, which he does periodically.
Give Free-I my love.