The eighty mile stretch of sea between the island of Hispaniola and Puerto Rico is one of the most difficult passages encountered in the Caribbean. It is fraught with tidal currents of strange twists and turns that are created by those two big islands on either side of it and by sand banks that extend out for many miles from both coasts. Most cruising boaters entering the Caribbean from the north do so via a stop at Samana in the northeastern part of the Dominican Republic, then continuing more than 150 miles across the Mona Passage to Puerto Rico without stopping. Under sail it means an even longer distance because of having to tack a zig-zag course into the easterly trade winds. Add this to the twisted currents and seas encountered while crossing and a haze in the air in this region which often blocks visibility until only a few miles from land, and you come up with a never ending array of hair raising stories from just about every boater you can talk with who has made the crossing.

Mona Island lies almost exactly in the middle of the Mona Passage and it would make an ideal resting place to split up the passage for vessels coming from Samana if it were only farther to the north. But for boaters wishing to take advantage of the island to break up the crossing into two more manageable pieces, they need to depart from the south coast of Hispaniola rather than the north. Currents are also less treacherous to deal with along the southern route. At the pleasant stop of Saona Island on the southeast coast of the Dominican Republic, boaters can sit and wait for a lull in the trade winds when seas are down to start their eastward crossing. This is an advantage which is not possible when departing from Samana. It is only about 40 miles from Isla Saona to the protected anchorage inside the barrier coral reef on the west coast of Mona Island. And from there it is another 40 miles to the popular and spacious cruising anchorage at Boqueron in Puerto Rico.

Mona Island is a part of the commonwealth of Puerto Rico. It is small, being only about five miles in diameter and with many steep and inhospitable looking cliffs which rise from the sea to a high plateau. The best anchorage is on the west coast north of Punta Arenas. This is Sardinero anchorage and it is protected by a barrier coral reef which has a narrow break of about 30 feet width. There is a pier just inside the opening on which there is one of a pair of range markers. This range was not exactly the way it was described in the guide books I had with me, but was clearly identifiable none the less, and once the two markers are aligned, the course for the opening in the reef is directly ahead. Under normal circumstances this is a well protected and peaceful, although small anchorage in clear water with a maximum depth of about eight feet.

Ashore, the whole island is crisscrossed with underground caves made by the erosion of coral limestone. The caves are full of stalactites, stalagmites and paintings made by the early native inhabitants. Pirates took over the island from the natives and used it as a base from which to launch raids on early treasure ships heading through the Mona Passage on a northerly route back to Europe. Today, Mona is a wildlife preserve with an air strip and ranger headquarters at Punta Arenas. There are wild pigs and iguanas roaming the island and a nice campground for visitors among the palm trees right near Sardinero anchorage.

Sketch of Sardinero anchorage on the west coast of Mona Island, Puerto Rico.

3D topographical map showing southwestern coast of Puerto Rico from Boqueron Bay in the foreground north to Punta Higuero beyond Mayaguez.