Being only 10Nm between Dover and Calais the Dover Strait is the most narrow part of the English Channel. Not only is it narrow but also the worlds most trafficated waters and with strict rules for traffic in the traffic zones we opted for heading outside of the main trafficlanes(inshore trafficzone). Having headcurrent of over 3knots for a while speed over ground was down to 2,9kts and subsequently part of our passage through Dover Strait took part in darkness. During such circumstances radar and updated charts are essential.