Today, things got even worse.

This morning, before heading out, I stood at shore and looked out to sea.

They say that if you stand on the foreshore and the flags are fluttering, don't go out.

A breeze on shore is a storm at sea.

Today the flags weren't fluttering, they were going wild - but, they were going wild in the right direction.

A storm blowing eastwards is a storm I could use.

So, we left Rye Harbour in a hired rib as the winds were too strong for our catamaran.

A mile offshore, as the rib crashed down the side of another wave and we were hit by yet more spray, the rib's skipper, Will, asked if we were alright.

I have swum in conditions far worse than this and in far more dangerous places around the world, so my team and I replied with an easy 'yes'.

Conditions were rough, but certainly still swimmable.

Another mile out to sea and the swell had grown at least another metre in height.

This time, Will didn't ask - "I'm calling the swim off", he said.

I looked at him in dismay.

I had to get those kilometres done today, I need to arrive in Dover on Wednesday!

We are running out of time.

The rest of the team were split. Kelvin, our photographer, agreed with Will. My skipper, Stephen, agreed with me but felt he must respect Will's decision.

I was outnumbered, so we turned back.

My team are here to get me to Dover. But they are also here to ensure that I get to Dover in one piece, able to campaign for cleaner and healthier oceans once I land on that beach.

The point of the Long Swim is not the swim, but the message behind it.

The pressure is on, though, in a way I've never experienced before. I've still not rounded Dungeness, and to compensate I will now need to swim day and night to make it to the end on time.

I must get to Dover, but I must also get there with energy left to fight this most important of fights, able to articulate it to the world's media.

But, because of this setback by the time I get to Dover, I will be exhausted.

From now on I need to conserve as much energy as I can, it's going to be three days of swim, sleep, repeat.

No swimming done - Total distance 305.9 miles (492.24km)