In this article, a concept of an application for a Fibre Bragg Grating sensor grid for Structural Health Monitoring the foremast of STS Dar Mlodziezy is presented and discussed. Research presented in this article are related to characteristics of the foremast of STS Dar Mlodziezy during her normal operation. The main goal of the research was to determine the strain/stress level of the foremast above the topmast crosstrees where three steel jib stays are mounted. To achieved this goal during the research special attention was paid to setting the sails and to taking in the sails.