Own vessel was a fully loaded VLCC with a draft of 21.9 metres.
As vessel was approaching the Sandettie Deep Water Route in the Dover Strait, it was observed on radar another vessel 1 mile astern overtaking with a CPA of 2 cables.
This vessel was identified and bound for Amsterdam with a draft of 7.5 metres (this information supplied by Cap Gris-Nez Traffic Surveillance). I called the other vessel on VHF radio and informed him of my position and that it is not recommended to use the DW Route if your vessel’s draft is not more than 16 metres or to overtake another vessel in the DW Route. The other vessel replied that if I could alter my course to starboard then he could pass safely down my port side. I replied that I would not alter course to starboard, but would continue to follow the DW track.
The other vessel continued to overtake on my port side and appeared to leave the F1 light buoy on his starboard side (so entering the South West lane of the TSS), and then passed clear of me.
As both Cap Gris-Nez and Dover Coast Guard Traffic Surveillance were broadcasting my position and progress through the Dover Strait I find it hard to understand why the other vessel chose to overtake me in the position he did. I pass through the Dover Strait on a fairly frequent basis.
It is increasingly common to observe vessels with drafts of as little as 5 metres using the Sandettie DW Route. I have never heard the Traffic Surveillance agencies, which monitor shipping movements in this area challenge a vessel as to why he is using the DW Route against the recommended guide lines.
I feel that if such a challenge were made over the VHF radio this would not only educate the vessel concerned, but all other vessels, which would hear the broadcast and so be similarly informed.
Certainly if a very large and deep draft vessel is in the process of transiting the DW Route, then any other vessel which can safely use the normal route should be informed by the Traffic Surveillance agencies to keep clear of this vessel.
This report is representative of six reports received by CHIRP related to the use of the Deep Water Route (DWR) in the Dover Strait. The rules of the Dover Strait Traffic Separation Scheme (TSS) state:
“The main traffic lane for north-eastbound traffic lies to the south-east of the Sandettie Bank and shall be followed by all such ships as can safely navigate therein having regard to their draught.”
The DWR falls within the UK Search and Rescue Area, but the French VTS at Cap Gris Nez has responsibility for monitoring NE bound traffic, including the DWR. Traffic advisory broadcasts are made by both Gris Nez and the Dover based Channel Navigation Information Service (CNIS), operated by the UK’s Maritime and Coastguard Agency (MCA).
A number of reports were sent to the MCA and a visit to CNIS was arranged to discuss the issues raised and to explore how they might be assessed and, if necessary, advanced.
Initially, a survey was conducted to ascertain the number of DWR transits made by shallow draft vessels and the reasons why the DWR was used in preference to the eastern branch of the NE lane. The information gathered from this survey was presented at the UK Safety of Navigation Meeting in November 2004 and resulted in a recommendation to strengthen the rules of the TSS which will be presented to the IMO during 2005