Revised November 2025

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These measures form an addendum to the club safety plan when there is higher than normal Fluvial flow so that the Tideway is under Red or Yellow flag conditions.

Jump to: Introduction | Ebb Tide Measures Under Yellow Flag | Ebb Tide Measures Under Red Flag | Flood Measures on Red or Yellow Flag

Under conditions of very high fluvial flow (ie that due to landwater coming into the Tideway at Richmond) the PLA classifies the conditions on the Tideway to be more dangerous than usual such as to merit a Yellow or Red flag. Effectively the height of the lowest tide is used as an indicator of the amount of fluvial flow. The higher the tide the higher the flow. The PLA set the flag status as follows.

Every day at 6 am and 6 pm the lowest tide reading for the Richmond tide gauge is taken for the preceding 12 hours.

• If the value is 2.6 metres or above then the flag is RED.

• If the value is 1.7 metres or above but less than 2.6 metres then the flag is YELLOW.

• If the value is 0 or above but less than 1.7 metres then the flag is GREEN.

The PLA classify use as follows:

Red - Very Strong Fluvial Flows

• Conditions are difficult and dangerous.

• All man-powered vessels are advised not to go afloat on the ebb tide.

Yellow - Strong Fluvial Flows

• Beginners, novices, younger junior (J15's and younger), or any weaker crews, and those that do not usually navigate on the tidal section of the River Thames not to go afloat on the ebb tide.

• All river users of man-powered vessels should navigate with extreme caution and consider whether it is safe for them to go afloat on the ebb tide.

Green - Average Fluvial Flows

• All river users to navigate with caution and maintain a proper look out.

Background

Higher flow velocities make it more difficult to control a rowing boat, make the water more turbulent and hence more prone to causing a capsize, and means that you can be swept onto an obstacle much more quickly than normal. However it needs to be remembered that flow velocities on the Tideway are always much higher than in most rivers because of the Tide so those who habitually row on the Tideway already have experience of fast flowing water and the faster water due to high fluvial flow is an incremental increase to this rather than a huge change. Despite this we must all take extra caution under high flow conditions. The factors and actions to control the risk are set out below. In any doubt the CWSA or deputy should be consulted.

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• Visitors discouraged from coming to the Tideway.

• Beginners, novices, younger junior (J15's and younger), or any weaker crews not to go afloat (As per PLA guidance).

• Larger boats to be preferred, only very strong, young (ie not older masters) and experienced athletes to go out in small boats (1x, 2x, 2-).

• Only large boats with experienced athletes should go above UL boathouse.

• Launches with outings wherever possible.

• Outings in the dark MUST have a launch, with no more than 2 crews per launch.

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• Visitors discouraged from coming to the Tideway.

• Launch with an approved club coach to accompany all boats, all boats to stay in sight of the launch, no more than three boats per launch.

• Every outing must be risk assessed by the coach with the crews and the results documented by email to the CWSA.

• Beginners, novices, younger junior (J15's and younger), or any weaker crews not to go afloat . (As per PLA guidance).

• Larger boats only (ie 4x/-/+ or 8), with strong, experienced athletes. It’s up to the coach to assess with the crews whether they are all competent and confident to go out. If anyone is Not confident that conditions are OK then crew does not go out.

• No boats above UL boathouse.

• No night time outings.

• No stopping within 200m upstream of a bridge or buoy.

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It’s likely that more crews than normal will be out on the Flood tide as they cannot go out on the Ebb Tide. This makes the Tideway more crowded, extra care needs to be taken to be in the right position and to keep a good look out.

The Direction of flow on the Flood tide can be very difficult to tell as the fluvial flow rate can be as strong or stronger than the Flood tide flow, resulting in there being no net flow.

Specific measures:

• Coaches to brief all crews before outings.

• Reminders on club systems under these conditions when there is a red or yellow flag.

• Club briefing on how to behave under these conditions ie watch flow markers all the time, keep a very sharp watch for others in the wrong place, stay to starboard side in the channel if unsure. Take care on bends

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