Portland

Introduction

This area runs from Weymouth to the west end of Chesil Beach. The major feature is, of course, Portland Bill, renewed for its violent tide race. Portland Harbour provides a sheltered area for a paddle. Chesil Beach provides limited interest for most paddlers.

Times of high water

Portland is a standard port.

West Bay: High water is 5 hours after high water at Dover

Tidal streams

Given the complexity and strength of the streams around Portland Bill, some detail is given below, including suggestions on times for passages in both directions. More information may be found in the tidal stream atlas NP257, reproduced in the excellent Pesda Press Guidebook South West Sea Kayaking and here.

Weymouth Bay: In Weymouth bay and near the Harbour the streams are weak, less than half a knot.

Portland Harbour North Ship Channel: The east going stream begins at 1 hours after high water at Portland. The west going stream begins at 4 hours and 15 minutes before high water at Portland. The east going stream reaches a speed of 1.1 knots at springs. The west going stream reaches a speed of 0.9 knots at springs. Flow is irregular and less than 0.5 knots between 4 hours 40 minutes after high water and the start of the west-going flow.

Portland Harbour East Ship Channel: The north-east going stream begins at 1 hours and 20 minutes before high water at Portland. The south-west going stream begins at 4 hours and 20 minutes before high water at Portland. The flow reaches a speed of 1 knots at springs. The out-going flow is irregular and only exceeds 0.5 knots between 1 and 4 hours after high water.

Off the eastern tip of Portland: The north-east going stream begins at 1 hours and 38 minutes before high water at Plymouth (devonport). The south-west going stream begins at 1 hours and 45 minutes after high water at Plymouth (devonport). The north-east going stream reaches a speed of 1.6 knots at springs. The south-west going stream reaches a speed of 3.7 knots at springs.

To the east of Portland Bill: A significant eddy flow forms during the east-going flow, so that flows are as follows: The north north-east going stream begins at 1 hours and 40 minutes before high water at Plymouth (devonport). The south south-west going stream begins at 20 minutes after high water at Plymouth (devonport). The north north-east going stream reaches a speed of 1.3 knots at springs. The south south-west going stream reaches a speed of 4.4 knots at springs.

Portland Bill: The east going stream begins at 2 hours and 20 minutes before high water at Plymouth (devonport). The west going stream begins at 4 hours and 5 minutes after high water at Plymouth (devonport). The flow reaches a speed of 6 knots at springs. Flows of 10 knots have been recorded close to the race. A violent race forms 400 metres off the point, most of which can be avoided by staying inshore. A large eddy forms on the down tide side of the point.

Offshore Portland Bill: The east going stream begins at 1 hours and 20 minutes before high water at Plymouth (devonport). The west going stream begins at 4 hours and 30 minutes after high water at Plymouth (devonport). The east going stream reaches a speed of 5.6 knots at springs. The west going stream reaches a speed of 7 knots at springs.

To the west of Portland Bill: A large eddy forms on the west-going stream, so that the flows are as follows: The north going stream begins at 5 hours after high water at Plymouth (devonport). The south going stream begins at 6 hours and 10 minutes before high water at Plymouth (devonport). The north going stream reaches a speed of 1 knots at springs. The south going stream reaches a speed of 4 knots at springs.

To the west of Portland near Clay Ope: The south going stream begins at 4 hours before high water at Plymouth (devonport). The north going stream begins at 5 hours and 30 minutes after high water at Plymouth (devonport). The south going stream reaches a speed of 2 knots at springs. The north going stream reaches a speed of 0.7 knots at springs.

Portland Bill - heading west: Although it may start a little earlier inshore, the westbound flow around Portland Bill begins around 4 and half hours after high water Plymouth. By 6 hours before high water Plymouth, a small back eddy has formed to the west of the point, attaining 0.4 knots at springs. The eddy flow increases to 2 knots by 5 hours before high water Plymouth. The sensible time window for a westbound passage is thus between 4 hours 30 minutes after high water Plymouth and 6 hours 30 before high water Plymouth.

Portland Bill - heading east: The east-going flow around Portland Bill begins around 2 hours before high water Plymouth, although the inshore flows to the east of the point are still slackening at this time. An eddy forms to the east of the point by 15 minutes before high water Plymouth, reaching 2 knots an hour after high water Plymouth. To allow time to clear the eddy area (which extends to the eastern point of Portland), a sensible time window for an easterly passage is from 2 hours before high water Plymouth to 1 hour before high water Plymouth.

Inshore Chesil Beach: The south-east going stream begins at 2 hours before high water at Plymouth (devonport). The north-west going stream begins at 5 hours after high water at Plymouth (devonport). The flow reaches a speed of 1 knots at springs.

To the east side of the Portland Harbour Breakwater: The north going stream begins at 1 hours and 30 minutes before high water at Plymouth (devonport). The south going stream begins at 3 hours after high water at Plymouth (devonport). The north going stream reaches a speed of 1 knots at springs. The south going stream reaches a speed of 1.6 knots at springs.

Notes

Access/Egress

Weymouth Harbour: (SY 677 790) g Launch at council slipway, park on commercial road.

Slip near Portland Castle: (SY 684 744) g Note the restricted areas within the harbour and the fees to paddle with the harbour.

Chesil Cove: (SY 683 732) g Note that swell can make this landing dangerous and there are no safer options for many miles to the west or without rounding Portland Bill to the south.

Suggested trips

Portland Bill: A serious trip that requires good understanding of the tidal streams and good timing.

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