The incident happened last Friday when the German and three companions surfaced to discover that their boat had drifted away on a strong current. As his companions became exhausted, Schumacher alone swam on for an hour until he reached the boat and alerted its occupants of the emergency.
It was an incident that had a profound effect on his normally buoyant outlook on life. "I've had a lot of accidents in racing cars, including that steering failure in Brazil, but that was the first time when I've ever thought that the end had come,'' he told journalists yesterday. "It was the first time that I've ever felt completely out of control.''
"We were out at sea and had dived to about 25 or 30 metres," Schumacher said. "I noticed that the anchor for the boat had moved but thought it might be quite normal. After about 45 minutes we went up and found the boat had gone. It was so far away, we could hardly see it and we waved and shouted to be rescued but they could not hear us.
"Then we started swimming and I realised I was the strongest of the four of us. It took me an hour to reach the boat and I was very frightened. For the first time in my life, I was thinking very seriously about my own death."
Schumacher, who finished yesterday morning's initial practice session in only eighth place, behind his team-mate Johnny Herbert, is racing with the same Elf fuel that Benetton and Williams used in Brazil, and which was found not to match its approved sample lodged with the FIA. Since Brazil, Elf has lodged a revised sample with the governing body and anticipates no further problems.
Grand prix racing may be back in Argentina this weekend for the first time in 14 years, but as far as the drivers are concerned after yesterday's acclimatisation sessions, it could just as well be Monte Carlo or Hungary.
"A good grid position here is going to be vital,' Damon Hill said, "just like it is at Monaco or the Hungaroring. It's a good circuit, and at the moment I have no complaints, but it's going to be very difficult to pass. It's going to be a race that's won or lost in the pits.''
"It's like a place called Albacete, where we went once and never again for an F3000 race,' said his team-mate, David Coulthard. "You're never hard on the power or hard on the brakes, you just use a little bit of each at a time because there are so many slow corners. I don't think we're going to see much racing.''
Both of them were relieved that the track, last used in this configuration for the grands prix held in the 1950s, is markedly smoother than Interlagos, home of the recent Brazilian Grand Prix. "The bumps are OK,'' Hill said, "but there is one just before the one quick corner. You approach this left-hander flat in sixth and there's this bump which temporarily ruins your vision just as you want to turn in.''
The gravel trap on the outside of this corner was the subject of debate initially, before small changes were made in time for yesterday's trials.
The Finnish drivers Mika Salo, the sensation of Brazil, and Mika Hkkinen both felt that the circuit suited their press-on driving styles. "It's very Mickey Mouse,'' Salo said, "but it's OK.''
Rain spoiled the second session, and is forecast again for today, but Hill remains optimistic. "If the race is wet it could be quite good. At least then you can get away with driving off the racing line when you're trying to pass someone.''