The development of fouling communities is object of world-wide research since the last half of the century. Biological fouling of vessels has been known since the beginning of man ’s maritime activities. Biological corrosión became a problem of concern when steel replaced wood as the primary ship construction material. The purpose of the present paper is to present a guide about biological aspects of fouling for the non-specialist (the non-biologist). The scope ofthis guide is to give some historical references, development sequences of the fouling community, abiotic factors influence, fouling problems, study methodology and enough elements to recognize the most important taxa with some pictures. Also, in relation to freshwater fouling, a basic approach and comments about exotic species introduction by ships are presented. A glossary and a broad bibliography on this subject are ineluded.