Maritime High School educates future seafarers, majority of whom will be looking for employmnet on the global labour market. In order to become more competitive and cope better with multicultural working environment on board ships all aroud the world, the school has decided to introduce the process of internationalisation through the European projects, international cooperation and continuing devolpment of the trainings methods in accordance with the requirements of the 21st-century educational systems. The first step was to include teachers into Learning Mobility of Individuals and provide training of teachers abroad. Thus the teachers gained language and digital competences as well as skills and knowledge necessary for school internationalisation, successful international cooperation and implementation of these activities into the existing curriculum. Furthermore, in order to achieve these goala, the continuous teachers' training and education will be required in the future as well. Also, since the results of the school self-evaluation process, state Matura exams and Pisa project have shown inadequate level of knowledge and skills of our students, one of the main objectives of our school has become development and improvement of language, mathematical, social sciences and digital competences of our students. Again, to obtain these goals, the continuous teachers' training will be required in order to introduce new methodolgies of teaching which are more suitable for the modern student. The school's project "School sailing internationally 2014/2015" included 7 in-service teacher's trainings and 3 teachers taking part in these mobilities. 1. “Best Practices Benchmarking” (Finland, March 2015) 2. "Le-MATH Course: Learning Mathematics through new Communication Factors" (Greece, March 2015) ” 3. “Effective Use of Technology in Teaching” (United Kingdom, September 2015) 4. “Let´s make our school more international: European Project Planning, Design, Management and Funding under Erasmus+” (Spain, November 2015) Acquired skills and knowledge have had a large and varied impact on the participants, students and the school. Written and oral communication in English has improved the language competences of the participants and reduced the fear of communication in a foreign language, thus making the process of future international cooperation and internationalization much easier. Futhermore, better language skills have fostered the use of various Internet tools, literature and audio-visual aids in teaching, accessible mostly in English. In addition, the students have been given the opportunity to acquire knowledge in more appealing way. Greater exposure to English is of utmost importance for our students, given the fact that English is a working language on board foreign-going vessels. Acquired competences in ICT technologies have enabled teachers to be more skilfull in the use of electronic devices and the application of Internet tools, social networks, platforms, etc. in the classroom. This approach to learning has increased the interest and motivation of students for acquiring new knowledge, and has encouraged them to actively participate in classes. Gained knowledge and skills have had a remarkable effect on personal and professional development of participants, self-evaluation of their own work, better understanding of deficiencies of the Croatian education system, particularly when it comes to student-teacher relationship. All the participants have shown greater need to improve the quality of teaching and collaboration with colleagues, parents and local community. In a nutshell, all the teachers had the opportunity to share knowledge amd experiences with their colleagues from other European countries, to learn about new educational systems, new methodologies in teaching, international colaboration and to improve their digital and language competences. The knowledge gained through the in-service course "Let's make our school more international: European Project Planning, Design, Management and Funding under Erasmus +" has enabled teachers to be more competent in project design, successful application, organization and implementation of international activities. The knowledge gained through the in-service course, "Let's make our school more international: European Project Planning, Design, Management and Funding under Erasmus +" has enabled teachers to be more competent in project design, successful application, organization and implementation of international activities. Also, contacts made at the course have already proved to be successful through the joint application for KA2 Erasmus+ activity.