62
SVN Solovelanet Global
rise and fall on that day in your location. The Nauti-
cal Almanac is the best source for this information.
You then need to decide how long the mooring li-
nes need to be. You do this by multiplying the tidal
range by three to give you the minimum length for
any of the mooring lines (so a 4m range means a mi-
nimum of 12m for the mooring lines). Now you can
tighten the lines, having assured that the boat will
rise and fall keeping station on the ladder but not
drifting away from the wall.
There is a trigonometric reason for the minimum 3:1
ratio. The following picture shows how little extra
rope is needed as the tide falls.
Of course a ratio of four or five to one would be even
better, but might be
not practicable on a
crowded quay.
Assuming a tidal range
1
1- Warps at high water
2 - Warps at low water
3 - Tidal range
4 - Extra rope you need to allow for
at low water
Alongside the wall in
Dunbar. Long lines are
key
2
2
3
4
