Bermuda's buses stink and are "revolting for tourists to drive behind'' a visitor claimed in a recent letter to the Premier.

"It's the most disgusting thing in an otherwise naturally beautiful island,'' penned the letter's anonymous author.

Also enclosed with the letter, copied to The Royal Gazette , was an article featured in the International Herald Tribune this month. It referred to catalytic converters used on diesel trucks to wipe out filthy fumes.

Converters placed in the exhaust systems of London diesel trucks cleaned up smoky emissions -- so much so that a white handkerchief placed over a bus exhaust comes away pristine white, the article claimed.

The Premier's office said the letter had been passed on to the transport department.

But director of public transportation Mr. Herman Basden dismissed the idea because of the exorbitant expense of buying and installing the converters.

A converter costs $6,500 in the United Kingdom but the price would be closer to $7,000 per bus by the time it reached the Island.

"It would hardly make sense,'' Mr. Basden said.

Furthermore, within the next five years, Bermuda's 106-strong fleet of buses will be replaced with new German manufactured vehicles.

"By the year 2000 the problem we are experiencing will have substantially diminished,'' Mr. Basden predicted. "The problem will eventually disappear.'' The German buses, of which 20 are already operating on the Island, have cleaner engines to conform with strict European Economic Community regulations governing emissions.

Buses purchased from 1991 onwards sport the new engines and produce little or no emissions.

"To buy a catalytic converter in my view, would be a waste of money because there are far more cars and bikes on the road producing far more pollution than we are,'' he said.

Ironically the visitor riding his moped was producing six times more noxious fumes than the bus he found so foul, Mr. Basden contended.

"Cars and bikes that run on petrol push out far more deadly fumes than we do,'' he said.

"Private cars put out poisonous carbon monoxide. The public sees the bus emissions and says, "that's awful'' but their vehicles are far more noxious.'' However, Mr. Basden was at haste to add that this did not mean he approved of filthy bus fumes. Nevertheless, he said, people should be aware of the full picture, meaning they should be aware of their own role in causing pollution.

Since 1988 when a new bus terminal was built, buses have benefited from "state-of-the-art testing'' for emissions. "It reduced complaints by several hundred percent,'' Mr. Basden claimed.