The known navigational systems in use and methods of navigational decision support perform information functions and as such are helpful in the process of safe conduct of a vessel. However, none of these known systems provides a navigator with ready solutions of collision situations taking account of all the vessels in the proximity of own ship, where the Collision Regulations apply. This paper presents verification results of NAVDEC — new Navigational Decision Supporting System created by research team from Szczecin Maritime University both for ocean going ships and pleasure crafts. Verification was carried out in real condition on board Motor Ferry ‘Wawel’ (m/f ‘Wawel’), which belongs to shipowner Polferries (PŻB). During the journey to/from Nynashamn system was tested from customer perspective. Few suggestions for improvements were issued, which were discussed in this article.