THE decision to go ahead with the 480-mile London-to-Paris Boat Challenge will be made tomorrow. Organiser Rob Platts hoped that the three guard boats and the rigid inflatable boat would be able to leave Guernsey as planned on Friday.

‘We won’t let the guard boats go if there isn’t a reasonable expectation that the rowers will be able to go on the Monday,’ he said.

The guard boats should arrive in London on Saturday and the custom-built 10m-long Geomarine Challenger rowing boat is due to leave by Condor tomorrow before it is driven to London.

‘We’ll be interested in looking at the weather forecast mostly for the time that the boats will be in the Channel – which is hopefully on the Monday and Tuesday. They should be reaching the Seine in the early hours of Wednesday.’

There are a number of factors affecting the rowers’ decision on when to start their record-breaking attempt. The team has taken into account factors including statistics on significant wave heights in the Channel. June usually offers calmer seas than September, which was the other month the team considered for the challenge. It is still a reserve.

Mr Platts said that the team would ideally like north-easterly winds to cool the rowers and help them on their way. They must also monitor the flow of the Seine because heavy rain in France could make it impossible for the team to row against the tide.

‘A significant restriction is that the rowers are not allowed to navigate the lower section of the river at night. This means that they have a 60-mile section of the Seine that must be navigated in daylight hours.’

To do this, the team has chosen a day when the flood tide at the mouth of the Seine starts at daybreak.

‘The only time this happens is during a spring tide, which increases the likelihood of choppy seas in the Channel.’

The team does have the advantage of long daylight hours as well as a full moon. If the weather is not right on Monday, then the start can be delayed for up to three days before it would have to be postponed until the next spring tide in mid-June.

Mr Platts said Wednesday morning weather checks would not determine the outcome but would give the team a first indication of whether the Monday start would be possible.

‘They won’t be great because no forecast is entirely accurate, but it’s the best thing we’ve got to go on.’

Final checks will be made over the weekend.