Waves The cover picture of the winter 1982/ 83 journal, number 482, the picture of The White Rose of Yorkshire returning to sea off Whitby Harbour, depicts vividly the dangerous sea conditions our lifeboatmen continually face around our coastlines.

The photographer, Theo G. R. Stibbons, has also clearly captured an illustration of the old mariners' tale of the 'seventh wave'. If, in the picture, the waves are counted from the pier ends seaward, then it is the third wave which The White Rose of Yorkshire is climbing.

Using the righthand edge of the photograph as a guide, the count continues, four, five, six and seven, which is the large wave just cresting white. In my childhood days I first heard my elders say that the seventh wave is the big one. On many occasions since I have witnessed this fact.—PHILIP SPENCER, Little Grange, 42 Roman Bank, Stamford, Lincolnshire.

The cover photograph of THE LIFEBOAT number 482 illustrates well the point that wave direction close to piers (see the position of the lifeboat. The White Rose of Yorkshire) can differ considerably from that further offshore (see the large spilling breaker).

Even a cursory glance at Admiralty Chart No 134 shows the cause: the shallows between Whitby Bell and Whitby Rock will induce a change in wave direction known as wave refraction.

In addition, and even more important, waves entering the deeper channel to the west of the shallows will swing round towards the shallows because of the same wave refraction phenomenon.

This factor is more important because it will induce crossing seas just off the piers with considerably increased wave heights where two waves or wave trains travelling in different directions intersect.

The cover photograph gives some indication of this phenomenon just north of the western pier.

This wave refraction/crossing seas process occurs in numerous places round the coast. While I have no doubt that lifeboatmen are well aware of such situations, those mariners to whose aid they go may be ignorant of the danger.

—p. HOLMES, BSc PhD, Professor of Maritime Civil Engineering, The University of Liverpool.

RNLB Shoreline I was very interested to read about the dedication of the lifeboat Shoreline which is now stationed at Arbroath as I have spent many happy summer holidays there and it was in this town that I first learned about the lifeboat's vital role. I would have liked to attend the dedication ceremony but, unfortunately, will not be coming to Scotland this year. Instead, I am enclosing a cheque for £155 which I should like you to use to buy protective clothing for a lifeboatman —please for an Arbroath lifeboatman! SHEILA MASTROMARINO, Mme, Geneva, Switzerland.

Support from The Netherlands I thought you might like to have this photograph (see below) of my husband, Mr A. D. van der Maas, to add to your collection of photos of people working to raise money for the RNLI. He weaves and sells these rope mats and does other ropework: ships' bell-ends in all patterns and sizes, even little 'mini' ones for keyrings (he must have made thousands of those)! And that is onlyone of many ways in which he raises money; he even talked a small group of friends into helping him to do the cleaning and dish-washing for a local club every week! In all he has raised about £350.

It may seem a trifle odd that a Dutchman works for the lifeboats in your country but he was originally, years ago, inspired by the enthusiasm and industry of the lifeboat people in Barmouth, Wales, where we were on holiday. My husband is a seaman himself, a retired Dutch Government sea pilot, so it is understandable that lifeboatmen everywhere are near to his heart. He has been a life member of Shoreline for some years.—MARY VAN DER MAAS, Mrs, Vlissingen, The Netherlands.

Long memory Glad to hear that the donations have been received. In 1940, on December 23, I joined the Royal Navy Section Beige till March 1946. Before that I served as a civilian diesel engineer on a ballroom barrage ship at Barry, near Cardiff, South Wales. On November 10, 1940 the ship was lost due to an enemy mine. I, together with four of my countrymen and one of the British crew, an Airforce corporal, got saved by people from the RNLI. I always felt an obligation to offer my thanks.—R. F.

POPPE, ex-leading signalman, RNSB, Oostende, Belgium..