The problem of this research is how to overcome the need for Maritime English textbooks that integrate English language skills (reading, writing, speaking and listening). This research aims to develop a valid, practical and effective English textbook to improve students' understanding of English in the maritime field. The research design uses the Research and Development (R&D) method. This research was conducted at the Banyuwangi Maritime Academy's Commercial and Port Shipping Management Study Program (KPNK). Data collection was carried out through documentation techniques, Focus Group Discussions, questionnaires, and administering tests. The instruments used include documentation sheets, validation, questionnaires and self-evaluation. Data analysis focuses on the validity, practicality, and effectiveness of textbooks with the parameters (1) level of validity, (2) level of practicality, and (3) level of effectiveness. The results of the study show that the English for Maritime textbook received very high validation from experts and user lecturers. The assessment by two experts showed a validity level of 96.96%, covering aspects of English language skills (reading, writing, listening, and speaking), appearance, presentation, material, and language, all of which are in the very valid category. Further assessment by user lecturers resulted in a score of 100%, which is also in the very valid category, confirming that this textbook is suitable for use without improvement. With high scores from experts and users, this book has been proven to meet the eligibility standards as a teaching material in supporting the mastery of English language competencies in the maritime field.