The tide ranks (difference between the high water and low tide) are very different for both coasts of Costa Rica, whose difference has to do with the marine bottom and the form in which the tide in both ocean basins oscillates. The tide rank average in our Pacific Coast is of 2,80 meters and in the Caribbean of 0,30 meters.

If the phenomenon of El Niño appears at the same time as an extraordinary astronomical tide, of the cycle of 4-5 years, the effects add and cause extraordinary levels of the sea which cause floods in the coast. This happened in 1997 when the Isla Damas in Quepos and other great floods throughout the Pacific Coast of Costa Rica occurred.