Four men seeking lobsters ran afoul of the coast guard this week because they had aboard a speargun.
A speargun is an accepted method of taking fish in many parts of the world, but using it is illegal in Costa Rica.
The Servicio Nacional de Guardacostas said that the four men found in the Gulfo Dulce in southern Costa Rica had four live lobsters in their possession.
They also had skin diving gear, such as flippers.
The coast guard is conducting sweeps of the gulfs checking the paperwork of boats there and how they are following the various laws. The agency also has been impounding crafts that appear to be unsafe.
The agency also reported Wednesday that its officers detained a tourist boat captain Monday because he is wanted on a murder charge by the Juzgado Penal de Osa . He was sailing out of Quepos and had two tourists on board, the agency said.