The Isles of Scilly’s Maritime Officer has said he fears a major shipping accident after a survey showed that many vessels sailing past the islands are taking short cuts.
Steve Watt, the council’s Tourism and Maritime Officer, told the BBC there could be disastrous results.
The survey, lasting a month, showed that more than 100 vessels pass between the Islands and the mainland every day.
Mr Watt said: “When those vessels tracks were recorded on radar we identified several tankers carrying chemicals, oil, propane gas which went the wrong way across the traffic separation zones.
“They were clearly taking short cuts.”
The Isles of Scilly was controversially left out of a Government list of 32 Marine High Risk Areas in March.
In March 1967 the 974-ft tanker Torrey Canyon, carrying 100,000 tons of crude oil, hit the Seven Stones reef near St Martins, causing significant environmental and economic damage.