Peter Legg and his crew felt helpless and frustrated because they couldn’t get to Zeebrugge to join the rescue.

Although Mr Legg and his team at Dover RNLI had a lifeboat, it was not powerful enough to take them speedily to the Belgian coast and would even have run out of fuel.

Instead they had to stay behind and help in whatever way they could on their side of the Channel.

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Mr Legg, who retired from the coastguard several years ago, said: “People started getting a bit fractious. They wanted to go and help because they were trained for that sort of thing. We all knew people on that ferry.”

But with the weather deteriorating that evening it was calculated that it would take 11½ hours to get there in a boat with a top speed of 70 knots and slowed down by conditions.

He said: “We realised even if we got there we wouldn’t have been much good because we would have been out of fuel, we would have been a fatigued crew, we would have been a hindrance.

“It was very frustrating. There we were, trained lifesavers and we couldn’t go and save lives.

“Everybody felt pretty rubbish. We felt as if we were ineffectual.

"We knew what we could have done but we couldn’t go and do it. It was just too far away, too prohibitive.”

Mr Legg, also a Dover coastguard, instead contacted colleagues at the Langdon base to help there. He was given a role in a specially set-up reception area to answer inquiries from the media and other authorities.

As the night progressed the information gradually filtered through revealing the enormity of the tragedy. He said: “It was difficult to get into your head that a big modern ferry with a trained crew was lying on its side.

“We didn’t yet know that 193 people had been killed.

“The towns of Walmer, Deal, Folkestone and Dover were all affected in some way. Everybody knew somebody who was working on the ferries or were on the Herald on the day.

“It particularly affected the people who continued to work for P&O Ferries (the successor company) at the time. They were thinking every time the ship heeled over, what’s happening, are we going too? Because we didn’t know what the whole cause was at the time.”

Mr Legg, now 70, says that the tragedy led to vast improvements in safety standards on ferries with both British and French operators taking heed of lessons.

He said: “The whole culture within the ferries changed. Training systems were updated with certain facilities on board such as tell-tale lights and cameras.

“It is now as safe as we can possibly make it. Obviously human error and technical faults still creep in.

"But by trying to keep the ships as well maintained as you can and everybody communicating, everything is based on the safety of the ships, the personnel who are working in them and the people who are being carried.

“It made the French think about their ferries as well and even now they still have meetings quite frequently with the Dover Strait User Working Group.

“Everybody that’s involved in the Strait, whatever nationality, can have a say and a place in the meeting.”

Mr Legg said that with all the training rescuers get, none can fully be prepared for a disaster like Zeebrugge.

He explained: “This was something you train for but when in does happen it is never like the book says.”

Meanwhile, if the Herald had capsized in deeper waters, hardly anyone would have survived, says Andy Roberts, a Dover coastguard on duty on the night of the disaster.

“Because of the shallowness the ferry only went on its side,” he said.

“In deeper water she would have sunk completely with minimal survivors.

"This was also March when the sea temperatures are at their coldest after months of winter.”

A total 193 of the 539 crew and passengers died in the disaster.

Mr Roberts, then 37, was part of the coastguard team on duty at the Dover station at Langdon.

His shift was meant to last from 8am to 8pm on March 6 but it went on to 6.30am the next day as he and colleagues helped co-ordinate the British side of the rescue.

Zeebrugge coastguards led the rescue, supported by others including their Dover counterparts.

Mr Roberts and his colleagues scrambled a helicopter from RAF Manston to fly over to Belgium carrying heat-seeking camera equipment.

The capsize had happened in evening darkness and also led to the ship’s lighting system being knocked out.

Mr Roberts said: “Imagine your own house turning on its side and filling with water and the lights going out.

"However long you had lived there you would not be able to know how to get out because you would be so disorientated.

“One man on the ship used the flashes on his camera to find his way to the exits until they ran out.

He said: “The telephone system in Dover fell over because of the amount of calls coming from relatives trying to find out what had happened to their loved ones.

“Our own station was inundated with calls from the local, national and international press.

“At the early stages it was not known what had happened. People may have thought it may have been just a bump or collision and they didn’t know if anybody had been injured.

“Imagine your own house turning on its side and filling with water and the lights going out " - Andy Roberts

“Because of the darkness there was no film of the stricken vessel. All we were told initially is that there had been some kind of incident.

“Passengers’ families were from all over the country and more than 1,000 came into Dover as early as that evening.

"Either they couldn’t get through on the phone or they simply didn’t know how to phone.

“They were so desperate they came into Dover with no money, accommodation or food.”

Mr Roberts believes many lessons have been learned, and improvements made since, for instance the introduction of passenger lists and the testing of crew for alcohol and drugs.

In addition video cameras are used to ensure the doors are properly shut.

He says: “The anniversaries can help as national recognition of what happened and could help the people left behind.

“But some people would not want to be reminded of that awful night.”

Mr Roberts, now 67 and living in Deal, is the deputy lifeboat operations manager for Dover RNLI. He was awarded an MBE for his voluntary work.