Men’s and women’s 10 kilometres events are due to take place in the morning on Lake Balaton.

Organising Committee head David Szanto said that more than 100 swimmers representing 30 nations would line up at the start.

"This is going to be a record participation in the history of this event," he said.

"Not only the quantity but the quality of the field is very high."

Also present at the opening press conference was Balatonfüred Mayor István Bóka, who said the recent heat wave in Hungary had allayed previous fears of water temperatures being too low amid some unusually cold weeks in late May and early June.

"The weather solved our problems," he said.

"The water will offer perfect conditions by Saturday.

"The experts predict 25 to 26 degrees,

"I think the swimmers will love it."

Hungary's Kristóf Rasovszky, who hit the headlines last August by achieving the unprecedented feat of claiming three medals – two golds and one silver – across the three individual events at the same edition of the European Championships in Glasgow, agreed that the weather and water could not be any better.

The Balaton Swim Club representative will be looking to show his best on home waters and turned down the chance to defend his title in Portuguese city Setúbal last week to concentrate on performing well.

"I wanted to be in the best shape as finally I wish to claim a medal at the home edition of the World Series," Rasovszky, who begun this year's World Series with a silver medal in Qatar's capital Doha and a bronze in Seychelles, said.

"My best result so far was a fifth place in Balaton.

"I want to make the podium this time.

"We had a fine training camp and I’m feeling I’m ready for the challenge."

Friend and greatest rival Ferry Weertman praised Balatonfüred, which was also the site of the open water events at the 2017 FINA World Championships where the Olympic champion finished first in the 10km.

He sees tomorrow's event as a good barometer in the build up to this year's FINA World Championships, scheduled to be held in Gwangju in South Korea from July 12 to 28.

"We always stage great battles with Kristóf and just like last year in Glasgow at the Europeans, I’m expected for another thrilling finish here too," he said.

"This is one of the best venues in the World Series and this is an excellent test for all of us before the World Championships as the field is quite strong just like in every other year."

Among the other notable names set to compete in Balatonfüred is the United States' Haley Anderson, a two-time 5km world champion and the 10km Olympic silver medallist at London 2012.