This report seeks to enlighten commercial trawl fishermen on modern fishing techniques involved in trawling on rough and irregular sea bottoms. It is the author’s observation that only chartered irregular features of the sea bottom are commercially exploited by Muro-Ami and handline fishermen while the unchartered features of the sea bottom remain virgin grounds waiting for exploitation by commercial fishermen using echo sounders. The author used two types of trawl nets in this fishing experiment to study the adaptability of bobbins and oval-shaped boards for each type of trawling on irregular sea bottom under Philippine conditions. The Western Visayan fishing ground is described in detail. Trawling positions made by M/V Lapu-lapu are indicated as well as the quantity of catch and its composition. The necessity and principle of echo sounding and its role in the Western Visayan Sea fishing operations are discussed. Echo sounding of the trawled area is roughly interpreted and presented in echograms. Based on the data available , it was concluded that the oval-shaped otter boards is the most appropriate otter board for rigging with any design of trawl net intended for trawling in rough and rugged sea bottom.