The purpose of this paper is to graphically represent semantic domain networks of maritime English near-synonyms as such displays can provide insights into semantic relations. A specialised corpus from international maritime communities was used. Keywords are extracted by comparing the Maritime English Corpus with the BNC Baby. Among keywords within the top 20 ranks, we focus on ship-vessel and maritime-marine. We use the MI3 score to identify collocates of the two pairs of near-synonyms and the Wmatrix web interface program to tag semantic domains. We create key semantic domain networks using the social network analysis tool NetMiner 4.0. The results show that some semantic domains are connected between the two pairs of near-synonyms, while others are not connected. The findings of the study indicate how semantic domain networks of keyword collocates and simple collocates help to distinguish near-synonyms through graphical representations of a corpus. The paper found that semantic domains with keyword collocates have a stronger tendency to connect two pairs of near-synonyms than those with simple collocates.