Go No Go Model

What influences the decision to go ahead or not?
River State

It is anybody’s guess how the situation on the Sunbury-Molesey stretch will turn out by race day or more particularly the Friday before, which is when we have to let people know if there’s going to be a change of plan.

We have a two step procedure. On the Wednesday before the race we will assess conditions and decide whether to continue to the Friday. On the Friday, unless we have cancelled on Wednesday, we will again assess conditions and decide whether the event can go ahead. The result of these assessments will be posted here.

We have an established decision model for River State which remains valid. The”Go/NoGo”model, which follows. This uses the EA Colour of Board in the first instance, and further influenced by (a) a Stick Test, measuring river speed at MBC, (b) the Flow Meter above Sunbury Lock, measuring flow in volume per second, and (c) the Lock Keeper’s advice. 

We also bear in mind the fact that strong winds can adversely affect river conditions (see below).


Precautions (or even difficult decisions) would be indicated if there were any of these:

  •  Dangerously high winds/gusts expected – particularly coming from the East, as these blowing against the stream down Platts Eyot can cause standing waves.
  •  Severe mist/fog, limiting visibility. As a rule of thumb, 200 metres would be the safe minimum.
  •  Severe cold. As a rule of thumb, an air temperature below 4 degrees Centigrade 
  •  Thunderstorm. Crews cannot remain on the river when lightning strikes are likely.
Who decides and how?

Meetings take place at the riverside (MBC and the Start) on Wednesday and Friday mornings prior to the event. Attended by Ted Bates (Secretary), Andrew Ruddle (i/c Racing), Pat Sinnott (Safety Officer).

Here is our decision tree:


Reviewed 15/1/24