LOCAL NOTICE TO MARINERS dated No 23 of 2014
Change to Tidal Flows in Cowes Harbour as result of the continuing construction of the new Breakwater.
The construction of the Cowes breakwater has reached a level of 3.5
metres above chart datum rising to 5m above chart datum by October
As predicted prior to construction the breakwater has had an
effect on the tidal flows in the Inner Fairway to the west and south of
the breakwater as follows:Inner Fairway west of the breakwater
the tidal flow at Nos. 1 and 2 fairway buoys is running in a westerly
direction, (expected from HW -3hrs to HW +3hrs) a tidal shadow with
significantly reduced flow will be experienced immediately west of the
breakwater in the Inner Fairway and extending along the foreshore in
front of the Royal Yacht Squadron.
HW-3hrs and HW vessels transiting the Inner Fairway between the Island
Sailing Club and the Small Craft Channel will experience a westerly
setting tidal flow of up to 1.25 knots which will have a tendency to set
vessels down towards the western shore.
Large vessels entering
or leaving the harbour during this period must be aware that due to the
westerly going tide at Nos. 1 and 2 buoys, the significant reduction in
tidal flow in the shadow of the breakwater and a possible westerly going
tide in the Inner Fairway between the Island Sailing Club and the Small
Craft Channel, that when the vessel crosses the boundaries of these
areas the differing tidal flows may induce a turning moment.
vessels will have a tendency to be set down towards the western shore
when within the westerly tidal streams. All mariners are instructed to
navigate with particular caution in the vicinity of the harbour entrance
and Inner Fairway.
A full set of actual tidal flows will be
recorded in November once the 2014 works have been completed and the
breakwater reaches its 2014 design height of +5m above chart datum. This
data will be published as soon as it is available.
A large image of the chart and full information is contained here