Setting off
We set off in glorious sunshine and apart from negotiating the set of three chain ferries at Torpoint, the pilotage up the lower part of the Tamar was straightforward. We arrived at the mouth of the Lynher a little early and picked up one of the empty moorings for a quick brew and a briefing from Tracey.
Once underway in the river there was a strong flood tide which swept us along at 6 knots over the ground. Tracey had a tendency to spend slightly too long below decks checking the chart, probably because we hadn’t allowed enough time for the planning process that morning. In a narrow channel it’s important not to take your eye off the ball, especially if travelling at speed, so I suggested we slowed down.
Approaching Sandacre point one of the first things I noticed was that neither Tracey who was in the companionway or Nick on the helm, were focused on depth – they were both absorbed in finding the next mark. The location of the echosounder low down on the helm station didn’t help. This was rectified by asking Erika to call out critical depths.
The headings that had been plotted between each mark were helpful given the long distances between buoys and large expanse of water in which to find them. However, in the early stages Nick obediently followed the compass and we encroached quite close to shore. I had to ask him to bring us back into deeper water. Headings must not be relied upon in a narrow channel
– any inaccuracies can be critical at this scale, whether that is of the helming, the original measurement or the position within the channel that you started from. Furthermore, it doesn’t take much of a cross wind or tide to set you off track. Use a heading as a rough guide and then ‘eyeball it’ to adjust for all the real-world factors.
In today’s modern yachts with fin keels and matrix constructions you need to be particularly vigilant about groundings. Repeated minor impacts can cause structural damage and even keel failure. This was tragically demonstrated by the loss of Cheeky Rafiki and her crew in the North
Atlantic in 2014. Having a well-calibrated echosounder is essential. There was no lead line on board and although Tracey was confident of the sounder’s accuracy, they should invest in one or make one themselves.
Depth is a key indicator of position in a narrow channel and one that’s often overlooked during a busy approach. Tom Cunliffe’s advice in the Shell Channel Pilot is to ‘feel your way up’ the river. This means keeping a constant eye on the echosounder and reacting quickly to unexpected readings. Dot-to-dot pilotage doesn’t work in a tortuous river: you need to add in the nuances of the contours by asking the helm to gradually come around towards the next mark instead of going straight there. Using a distance off is also a useful technique – give instructions such as ‘Stay within 10 boat lengths of this bank, it’s shallow further off,’ or, ‘Stay a couple of boat lengths off that mark, it dries out.’