Sounding Leads
Three lead sounding weights from the wreck
By the time of the Alderney ship English seafarers had a range of instruments, tables, charts and other devices to help them arrive at their destinations accurately, safely and as expeditiously as possible. Of the navigational devices available to the Tudor ship-master 'probably the most ancient', wrote David Waters in his majesterial workon The Art of Navigation in England in Elizabethan and Early Tudor Times, 'was the lead and line for finding the depth of water. His forbears had needed it before ever they felt the need for determining direction. The first necessity for the seaman in the opaque waters of the norhtern seas, with their varying depths caused by the rise and fall of the tide, is a means of finding how much water he has under his ship and of detecting the presence of hidden rocks and shoals. This he did with the lead and line'.
Thus far, three sounding leads have been recovered from the Alderney wreck. Each was long, truncated and hexagonal-side with concave hollow in its bottom. At the top there was a perforated lug to take a line.
The sounding lead did not only give depth but also, when conditions were right, they sampled the seabed, the texture, colour, taste and smell of which could could help a master determine his position in relationship to the coast, and thus what course might best be steered in order to make safe landfall. This was done by smearing the hollow with tallow to which would adhere the mud, sand or gravel of the seabed. If the bottom was 'oozy' the hollow was 'armed' with a piece of white woolen cloth that had been greased with tallow. When the lead came up clean the leadsman knew he was over rock.
The importance of sounding in coastal naviation was made clear in The Rutter of the Sea (1528), the first sailing drections published in English, translated from the French by Robert Copland and published in 1528. In the rutter, whch was intended for ships in the wine trade between Bordeaux and Cadiz, it gives the soundings 'that ye shall find' along the route including, of course, lower England where it faces on to the Channel. It was 'soundyng ledes with lynes' that gave the first warning that one was over the contineltal shelf and perhaps standing into shallows, rocks and races. Copland gives the depths and bottoms after passing Ushant at the top of the Bay of Biscay and heading into the Channel towards the Lizard, in Cornwall, the southernmost tip Egland:
When ye be at lxxx fadome ye shall finde small black sande and yee shalbe at the thwart of lezarde.
When ye be at lx or lxv ye shall finde white sande, and white soft woormes And ye shall be very nigh to Lezard.
The first illustration of a lead and line features, with a number of other navigational intstruments of the day, on the frontispiece of Wagenaer's The Mariners Mirrour (wherein may playnly be seen the courses, heights, distances, depths, soundings, flouds, and ebs, rising of lands, rocks, sands, and shoalds, with the marks for thenterings of the Harboroughs, Havens and Ports of the greatest part of Europe: their several traficks and commodities. Together with the Rules and instrumets of Navigation) that was produced in 1588 just four years before the Alderney ship. It revolutionised navigation charts for north-west Euope. It was particularly concerned about sounding when appraoching particularly dangerous destinations ('By the law of the Sea, such places are exspressly forbidden to be entered without sounding ...')
The first description of the lead and its usage is to be found in Captain John Smith's Sea Grammer of 1627 and Mainwaring's Seaman's Dictionary, which was written in the early 1620s but not published until 1644. Both distinguish between deep-sea, or 'dipsie', leads for use when approaching the continental shelf, and another of half the weight, or less, for use in shoal water of less than 20 fathoms. The dipsie lead, according to Smith, had a thin line of 150 fathoms that was marked off with knots that had little strings attached, first at 20, and then at 10 fathom intervals. Mainwaring gave this lead a weight of 14 lbs and a line of 200 fathoms. Both gave the weight of the shallow lead as 7 lbs and a foot long with thicker line which was marked off at 2 and 3 fathoms with black leather markers, and at 5 and 15 fathoms with white fabric, and at 7 with red fabric and at 10 with leather.
For deepsea soundings the ship was hove-to and either a boat was used, or else the lead was swung from the weather side bow with a line that was coiled at intervals, clear of the weather rigging, all the way to the poop. A seaman was staioned with each coil which he released ...
