The Mayor's plans for cleaning up the air we breathe are commendable, but have made no mention of waterborne traffic through central London. Every ferryboat, clipper, tug, liner and narrowboat is powered by a highly polluting diesel engine. There may be a few exceptions that have electric motors, but these are very rare. On the Regent's Canal alone, hundreds of narrowboats are moored, or driven between Limehouse and Little Venice, and the number is increasing annually. Sorwar Ahmed, of the Canal and River Trust will be able to confirm exact numbers, as he has been leading the survey into congestion on the canal for some time. If diesel powered cars, buses and lorries are to be banned, why not boats as well? Thousands of residents, walkers and cyclists are affected and will wonder why no action has been taken to alleviate canalside pollution. I have already emailed the mayor on this subject, but not yet received a reply.