Shipping accounts for 99.8% of Japan's international imports and exports. In other words, it is at the heart of the Japanese economy. The language used on ocean-going vessels that ply these international shipping routes is maritime English, a specialized form of English. However, many of the maritime English dictionaries currently available only describe English words and their translations, and are not designed to provide a guarantee of quality in learning. The reason for this is that there is little competition in the production process, as no dictionary-making experts are involved, and there is a guarantee of a certain number of purchases by maritime educational institutions, etc., so updates are rare. On the other hand, the awareness that general English dictionaries, especially English-Japanese dictionaries for learners, are products is high, and there is a stance of responding to the convenience of users. One of these is the description of a Semantic Tree. The purpose of this is said to be to assist in understanding word meanings. In this paper, focusing on existing maritime English dictionaries and several English-Japanese dictionaries for study, an ideal form of maritime English dictionary is developed from a cognitive perspective, especially metaphors. Reforming the descriptions in maritime English dictionaries means contributing to the shipping industry.