Hey patthebrat!

Thank you for your interest in DIY Costa Rica! I love your username, by the way. 😉

I’d estimate the total travel time to be around 6.5 hours, though the exact time will depend largely on road conditions (as you note) and how long you wait at the ferry dock for the boat to depart. For example, if you arrive at the dock a full 2 hours before the ferry is supposed to leave, obviously 2 extra hours would be added to the amount of time it takes to travel between Playa Herradura and Ostional via the ferry route. My estimate above and breakdown below assume that you arrive within one hour of when the ferry actually departs. Here’s a rough breakdown of the timeline:

Estimated drive time between Playa Herradura and the dock in Puntarenas: 1.5 hours
Estimated time it takes to check-in for the ferry ride, board your vehicle, and start departure: 1 hour (you must arrive at minimum 40 minutes before departure)
Estimated ferry ride duration: 1 hour
Estimated drive time between Playa Naranjo and Ostional: 3 hours (roadwork is ongoing in the area, so it’s possible this drive time will be less by the time you visit)
TOTAL ESTIMATED TIME: 6.5 hours

Note that the route between Playa Naranjo and Ostional often requires a river crossing around Nosara. The road is sometimes closed during the wet season, but it can also close during the dry season when the area receives rain. Here’s a helpful resource we use, which relies on locals in the area to comment on the status of the road in live time: https://www.facebook.com/groups/773768890053713

Also, here’s a link to Coonatramar, the company that runs the ferry between Puntarenas and Playa Naranjo: https://coonatramar.com/producto/ferry-puntarenas-hacia-playa-naranjo/ – they accept online reservations for tickets, which is a great way to ensure you’ll have a seat on the ferry on the day and at the time you wish to use it.

Pura vida! 🙂