REGARDING the new safety measures British Waterways are taking, since the tragedy on the Leeds-Liverpool canal in 1998, in which four people drowned.

I wish to express my opinion based on many years boating on the waterway.

Canal locks have 'top' and 'lower' gates, each with paddles to let water in or out. The method of going down a flight of locks is to close the lower gate, fill the lock with water, and when level, open the top gate, and sail the boat in, closing the gate after and run the boat up to the lower gate, leaving the engine in drive to ensure it stays there and does not drift backward.

The construction of all locks are that as the top gate is shorter than the lower one, the top gate sits on a 'sill' which protrudes some two or three feet into the lock.

I believe the cause of this terrible accident was because all the crew got off the boat intending to operate the lock. But as the water level dropped, the boat would drift back so that the rear was over the 'sill' and rested on it.

As more water went out, the front of the boat would dip down and go under the water, giving the occupants no chance.

A working knowledge of locks is vitally important, and the hirers should give some instruction before the crew go on the boat.

The procedure of going up and down locks is different. Going up, you sail into the lock, close the lower gate, run the boat up to the sill, leave in drive (a competent boater should be on the boat in the lock at all times, up or down); open the left-hand ground paddle, which lets the water swirl under the boat, thereby holding it against the lock side.

As the water rises, keep the boat up against the gate. When the levels are the same, with more power on, the boat will open the lock helping the crew. On leaving, close all paddles and gates.

I am surprised at the measures brought in by British Waterways in restricting the use of the top paddles in the upper door, for they are only used when going up the flight. When the accident happened, the boat was going down.

British Waterways' measures will cause problems for boat users and are irrelevant to the cause of the accident, since door paddles are only used when a boat is going up a flight.

S COBB, Manchester Road, Accrington.

Footnote: Terry Horan, waterway manager for the Leeds and Liverpool canal said: "I thank Mr Cobb for his comments. However, his facts about the Gargrave incident and the reason for the safety measures British Waterways have taken are incomplete.

"This is a national review of waterway safety and not just a response to a single incident. Also, water inundation from these paddles has been the primary or major contributory factor to every incident we have recorded over the last five years.

"If Mr Cobb would contact me on 01282 456978, I can bring him up to date with the many recommendations that are currently being reviewed."