The Gulf of Guacanayabo is a bay

Headlands and bays

Headlands and bays are two related features of the coastal environment.- Geology and geography :Headlands and bays are often found on the same coastline. A bay is surrounded by land on three sides, whereas a headland is surrounded by water on three sides. Headlands are characterized by high,...

 along the southern coast of Cuba

Cuba

The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...

, bordered by Granma

Granma Province

Granma is one of the provinces of Cuba. Its capital is Bayamo. Other towns include Manzanillo and Pilón.-History:...

 and Las Tunas

Las Tunas Province

Las Tunas is one of the provinces of Cuba. Major towns include Puerto Padre and Amancio, as well as the capital, Victoria de Las Tunas ....

 provinces. It is located at 20.5°N 77.5°W.
The largest port on the bay is Manzanillo

Manzanillo, Cuba

Manzanillo is a municipality and city in the Granma Province of Cuba.It is a port city in the Granma Province in eastern Cuba on the Gulf of Guacanayabo, near the delta of the Cauto River...

, ad to the north-west, the gulf is bordered by the Jardines de la Reina

Jardines de la Reina

Jardines de la Reina is an archipelago in the southern part of Cuba, in the provinces of Camagüey and Ciego de Ávila.It was named by Christopher Columbus to honour the Queen of Spain. Jardines de la Reina was established as a national park...

 archipellago. Cuba's longest river, the Cauto River

Cauto River

The Cauto River or Río Cauto, located in southeast Cuba, is the longest river of Cuba.It flows on a total length of from the Sierra Maestra to the west and north-west, and enters the Caribbean Sea north of Manzanillo. However, it provides only of transport waterway...

 empties in the Gulf of Guacanayabo.

It is also where, in 2005, Hurricane Dennis

Hurricane Dennis

Hurricane Dennis was an early-forming major hurricane in the Caribbean and Gulf of Mexico during the very active 2005 Atlantic hurricane season. Dennis was the fourth named storm, second hurricane, and first major hurricane of the season...

had its peak effect.