3 February 2026

Presenter Iolo Williams has said the Sea Empress disaster was the “worst event” he’s ever witnessed.

The Springwatch and Iolo: Natur Bregus Cymru host’s comments come in a new S4C documentary to mark 30 years since what was at the time one of the largest oil spills in the world. 

Dŵr Du: Trychineb y Sea Empress (Black Water: The Sea Empress Disaster) will be broadcast on 3 February at 21.00 on S4C and will be available to watch on S4C Clic and BBC iPlayer, with Welsh and English subtitles. 

The Sea Empress was an oil tanker that got into difficulty near the port of Milford Haven, Pembrokeshire, in 1996. 

At the time, Milford Haven was one of the world’s most important ports and the second biggest of its kind in Europe. 

After the Sea Empress collided with underwater rocks, 72,000 tonnes of oil spilled into the sea – the equivalent of 32 Olympic-sized swimming pools. 

Iolo Williams worked for the RSPB at the time of the Sea Empress disaster. 

“When I first heard the news, I thought is it true?  I went down to Pembrokeshire the following morning.  I put the radio on in the car as I drove down.  It was on everywhere, every channel, Radio Cymru, Radio Wales, Radio 1, Radio 2, Radio 4, everything talking about this,” Iolo said. 

“No one knew exactly how big this disaster was going to be at the time.” 

The eyes of the world were on Milford Haven in the aftermath of the disaster, with journalists from right across the world descending on St Ann’s Head. 

“I was sleeping in the car because there was no hotel, there was no B&B or anything like that, they were full of press,” Iolo added. 

After three weeks in Milford Haven, the Sea Empress was moved to Belfast to be fixed. 

But 30 years after the disaster, Iolo believes it’s important that what happened on the Pembrokeshire coast isn’t forgotten.  

“For centuries we’ve used the sea like a dumping ground.  I love Pembrokeshire, it’s one of the most beautiful areas in Wales without a doubt, but I’ll never look at Pembrokeshire in quite the same way again,” Iolo added. 

“30 years later, it’s important that we all remember and re-tell the story of the Sea Empress, so that we never forget what happened to our wildlife, that we never forget why it happened.  

“I’ll always say that if there is a disaster, if you have a difficult period in your life, if you can go through that and learn something, at least something good will have come out of the bad.”