The Quai des Trois Fontaines is a berthing area in Chooz, France, which was designed for 80 m long vessels (CEMT Class IV) plying the River Meuse. A turning basin is located in front of the Quai des Trois Fontaines to allow vessels to turn before loading at the quay. Real time simulations on a dedicated inland ship manoeuvring simulator at Flanders Hydraulics Research were carried out with experienced skippers to study how the safety of the turning manoeuvre could be improved and which measures are required for safe manoeuvres with longer vessels, i.e. vessels of 85 and 90 m in length. In the first phase of the study, turning manoeuvres of CEMT Class IV vessels of 80 m, 85 m and 90 m long were studied in the existing environment. The manoeuvres were evaluated based on different safety criteria and on the feedback of the pilots. The real time simulations have shown that the actual design of the turning basin is suitable for the 80 m long vessels in any hydro-meteorological condition. However, the manoeuvres become risky with 85 m long vessels under certain conditions and impossible with longer ships. Although the current can be very strong on the river Meuse, the local width turned out to be the most critical parameter. In the second phase of the study, measures were proposed to allow the safe turning of 85 m and 90 m long vessels. Local widening of the river to 100 m and to 105 m were proposed for 85 m and 90 m long ships respectively. A third proposed measure is to provide a fixed point near the end of the quay, to which the vessels can attach and around which they can then turn.