Pacific coast dwellers are facing a strong sea through the end of today.
The national emergency commission said that the entire Pacific coast would be affected with waves from 2.4 meters to 3.2 meters and perhaps as high as 4 meters, more than 13 feet.
The agency said it was relaying data from scientists at the Centro de Investigación en Ciencias del Mar y Limnlogía at the Universidad de Costa Rica.
The seas will not be particularly dangerous for small boats but they can be dangerous for bathers and operators of small boats along the beach and at river mouths, said the commission.
The case was said to be a tropical cyclone to the south. However, wave height will be higher in the northern Pacific coast, it said.
The commission also warned of beach erosion.
The heavy seas will create more dangerous rip tides that sometimes trap swimmers.