Had a look for ports of entry on the Pacific coast of Columbia - the only one I could find that resembled a Port - ie: ships , gantries, cranes etc.. was :-
Bun, in the Coastal city of Buenaventura - Valle de Cauca ---- Lat 3.8 N x 77.28333 W.
There must be others - but the coastline doesn't appear to be that welcoming.
The Citizens of the following countries do not need a visa to enter Colombia as a tourist:
Andorra, Antigua and Barbuda, Argentina, Austria, Autralia, Bahamas, Barbados, Belgium, Belice, Bolivia, Brazil, Canada, Chile, Costa Rica, Denmark, Dominica, Ecuador, El Salvador, Finland, France, Germany, Granada, Greece, Guatemala, Guyana, Honduras, Iceland, Indonesia, Israel, Italy, Jamaica, Japan, Lichtenstein, Lituania, Luxemburg, Malasia, Malta, Mexico, Monaco, Netherlands, New Zeland, Norway, Panama, Paraguay, Peru, Philipines, Portugal, Romania, San Marino, Santa Lucia, Singapore, Slovac Republic, Spain, Sweden, Switzerland, Trinidad & Tobago, United Kingdom, Uruguay, USA and Venezuela
If your country is not on this list you will need a visa .