The Newcastle-based company was ordered last year to pay out $26 million over European river tours affected by floods in 2013.

The new class action filed in the Supreme Court by Somerville Legal claims up to 3000 customers aboard 21 different cruises had their 2018 holiday, cruising through Europe down the Rhine and Danube rivers, interrupted by severe drought.

Instead of the luxury cruising, passengers say they were bustled onto coaches, travelled down freeways and stayed in second-rate hotels because the droughts meant the waterways were too low to accommodate large ships.

One of the affected tours, a 15-day Scenic Jewels of Europe cruise from Amsterdam to Budapest starting November 7, 2018, became a trip made up of four cruising days.

According to the glossy brochures, the original itinerary included a trip down the meandering rivers of the Rhine, Main and Danube, through forested hillsides, idyllic vineyards and romantic towns, "creating memories that will last a lifetime".

On board the luxuries were to include butler service for every suite, complimentary beverages all day, every day, and a complimentary mini bar.

One guest on the Jewels of Europe tour said they were swapped from the promised vessel, the Scenic Opal, to another ship after two days of cruising.

They did a two-hour bus trip to Bopard, a public ferry trip through the Rhine Gorge to St Goar, and another two-hour bus trip to Ruesheim, followed by another bus trip to Frankfurt.

They said they were allowed two drinks on the ferry but they claim there were only three staff for 160 passengers, so they had difficulty getting served.

Once back on the ship, it made an unscheduled stop, and the toilets didn't work for half a day, they said.

They did a tour of World War II sites in Nuremberg, and were later told by way of a letter that the tour would end at Regensburg because cruise ships couldn't get through, and the rest of the journey would be taken by bus.

The last four days of the tour were spent in a hotel in Budapest.

Passengers are claimed to have paid up to $20,000 for the trip.

Scenic Tours declined to comment on the legal action.

Somerville Legal managing director Ben Hemsworth said the matter was still in the discovery phase. One of the key documents being sought from Scenic is a list of passengers aboard the 21 affected cruises.

Being an open class action, everyone who falls within the description of those on whose behalf the claim is being brought are included automatically once it is filed, Mr Hemsworth said.

He said that number is up to 3150 or more, based on an average number of 150 passengers per vessel.

Once the list of names is produced, Somerville Legal says it will contact each passenger to give them the opportunity to opt-out of the class action.

Mr Hemsworth said to date, since the action was first filed in August, 2022, the proceedings have focused on whether or not passengers who signed up to tours via overseas-based companies were legitimate members of the class action.

He said Scenic had argued that those who made contracts in Australia were the only legitimate members of the class action.

That application was heard in the Supreme Court in April, and court records show it was recently dismissed by Justice Peter Garling. Scenic Tours is expected to file a defence by April 19.

It follows on from a similar class action against the cruise company, relating to promised luxury cruises in 2013.

In that case, led by Lake Macquarie-based school teacher David Moore and involving 11 ships and which took 10 years to settle, Scenic Tours were last year ordered to pay out $26 million.

Those affected received staggered amounts depending on the degree of disruption to their tours.

Mr Hemsworth said the second class action related to very similar circumstances, except the underlying issue was drought, not floods, as was the case in 2013.

"We will allege that they've embarked on a course of action where you could say that they've done it again," Mr Hemsworth said.

In the previous class action, 1223 people successfully sued Scenic Tours after proving their "expensive, luxury river cruises" through Europe in 2013 turned into "cheap, second-rate bus tours".

Heavy rainfall in France and Germany in April and May 2013 caused extensive flooding and water levels on the Rhine, Saone, Rhone and Danube rivers rose so high that cruise boats were unable to operate as scheduled for about six weeks.

The 13 affected tours included Amsterdam to Budapest, Amsterdam to Basel and the rivers of southern France.