We loved doing the gorge! Totally worth the effort! If you are on a cruise, it is doable. Prior to the trip, rent a car with Europcar in Pointe du Bout. It’s the only car company we found that will let you return the car the same day. We paid about 55 euros which included full insurance. Also purchase good road map of Martinique or get a gps from Europcar, if they offer it. We used a Michelin map we got from Amazon.
Once in Martinique, get off the ship ASAP and over to the Vedette Tropicales ferry. It’s on the middle angled pier just east of the Pointe Simon Cruise terminal. If you are on Celebrity, that cruise pier is a 15-20 walk west to the ferry pier - just on the other side of the fort. There is very good signage that says, “Ferry to Beaches”. Once there, get roundtrip tickets to Pointe du Bout. There is a ferry schedule online at Vedettestropicales.com Make sure you get the ferry to Pointe du Bout. The ferries have more than one destination.
Once at Pointe du Bout, it’s like a 2-3 minute walk to Europcar. I want to say it’s on Rue du Chacha. Streets aren’t obvious. It’s not a freestanding building on its own. Just look to the left as you walk out of the ferry area onto the town street. Or ask.
I’ve attached a map where Pointe du Bout and Gorges de la Falaise is marked. It takes about an hour and a half to go from Pointe du Bout to the Gorges de la Falaise. Directions are towards places rather than East, West etc. We took D38 to D7 towards Rivière Salée, then the N5 towards the Aeropuerto or Le Lamentin, then the A1 towards Fort-de-France and then the D41. We then took the N3. There was a place on the N3, near the beginning where we weren’t surely we were still on the N3 (we had taken the road going toward the right at sort of a T place,) but there was a sign within a mile or two for N3, so we knew we had taken the right road. After that we just followed the N3 also called the Route de la Trace. (Look it up.) Very windy, but scenic. Gorges de la Falaise is a few kilometers beyond Le Morne -Rouge. There is a sign and it’s on the left down a non-descript road. Cost is 10 euros each cash. Be in a bathing suit, have a waterproof camera and good soled water shoes or sneakers you don’t mind being under water. Stairs are down are steep, but I did it and I’m almost 60. Read other reviews for more info on the gorge. Phone numbers for the gorge and the restaurant next door are 0596533653 and 0596533561. They will close if it rains.
Going back, be aware that traffic in Fort-de-France can be bad. Leave plenty of time. We had no problem. We took the 8:45am ferry and were able to catch the 3:15pm ferry back. Plenty of time to walk the 15-20 minutes to get back for the all aboard at 4:30 pm on Celebrity pier. Note that after the 3:15om ferry, there is not another back to Fort-de-France til 4:15pm.