The article covers the possibility of applying digital technologies for mapping seafloor vegetation for coastal sea zone. Submitted method allows promptly and accurately receive information about distribution of algae species. Laspi bay is distinguished by biological diversity, an abundance of unique habitats of seafloor vegetation, where sea grass and algae communities are represented. Based on these qualities it was chosen as a model region for mapping macrophytes distribution. Aerial photography using an unmanned aerial vehicle (UAV) and hydro-botanical studies were conducted in the summer of 2019 year. The distribution map of macrophyte made based on aerial photos, while composition and structure were determined though hydro-botanical surveys. Five transects were laid in the bay, hydrobotanical profiles were compiled. Five seafloor plant communities identified for mapping. Digitized boundaries were set using software package QGIS version 2.18.12. Based on boundaries distribution map was made. The spatial patterns of the distributionof dominant macrophyte species (Cystoseira, Phyllophora and Zostera noltei) mapped along with quantitative characteristics.