I'm a fan of Bayahibe too. If you have the time, you could do one of the half day boat trips, like to Catalina Island, and then have half a day in town walking around, getting some food and drink and feeling like you'd seen a century old Dominican fishing village/booming tourist destination. I have a couple of hundred pictures of my stay there in January posted at
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If you want to see some history while enjoying beach time and cervezas in Bayahibe, you can take a walk out to the point by the embarkation beach to where an outdoor museum has been set up at the site of the oldest discovered civilization in the Caribbean (dating to 2000 BC). You'll see some great views and the Rose of Bayahibe, a plant found only on this point (but now transplanted to the resort hotels in the area to keep it prospering). I have pictures of that posted at
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I know that some cruisers were able to book a tour to Catalina Island with Seavis Bayahibe in January that catered to their hours in port, leaving the beach in Bayahibe at 8:30 a.m. and returning by 1:30 p.m. You can possibly arrange something similar.
There is also a public beach at the Dominicus townsite. It hasn't the benefit of Bayahibe nearby and I think the beach is smaller, but it's still beautiful and might be an option for you.
Kaki