What many spectators might not realise, however, is the logistical and financial challenge behind hosting these events in large aquatics centres. Up until 2008, when hosting a swimming event, the choice in 80 per cent of cases was to build a new, large arena. 

In the last fifteen years, sports institutions have changed their approach!

I’m talking about the use of temporary pools. As a former Canadian national swimming team coach (Los Angeles 1984, Seoul 1988 and Barcelona 1992) and as a member of many aquatic organising bodies and associations, I would like to explain in plain terms why we now see that for major aquatic events like the Olympics, World Aquatics, European Swimming (LEN) and even the USA Swimming for the US trials, organisers are choosing to utilise big arenas and install temporary pools for their competitions.

Initially, the aim was simply to bring the major swimming competition to the general public in order to popularise aquatic sports. 

However it soon became clear that the move offered the opportunity to significantly enhance ticket revenue by seating more spectators, yet the Organising Committee could avoid building costly permanent facilities with a minimum of ten thousand seats, designed predominantly for the once in a lifetime event.

The last two permanent Olympic venues (London 2012 & Tokyo 2020) cost around half a billion dollars each! 

Rio 2016 was an enclosed temporary venue and cost approximately $38 million (£31.3 million/€36.1 million). 

Major sports institutions have realised that renting existing large arenas and installing temporary pools for the event is a cost-effective alternative. 

Paris has resisted the temptation to build an aquatics venue to meet the needs of the International Olympic Committee (IOC) and World Aquatics and instead is building a community complex in Saint-Denis which satisfies the need of the aquatic sports other than swimming. 

The swimming events in contrast will be staged in La Défense Arena which can host 18,000-20,000 spectators and still have room for a full-size Olympic warm-up pool.

This all started in Brazil in 1995 when it hosted the World Short Course Swimming Championships and built a temporary venue in Copacabana Beach seating 10,000 spectators. 

Ten years later USA Swimming held their 2004 Olympic trials in a temporary venue built on a car park in Long Beach, California. 

The picture tells the story and now the US Trials regularly seat more spectators than at the Olympics themselves. 

The money earned from spectators easily covers all of the construction and operation expenses and can be quite profitable, but that’s not the reason USA Swimming makes such a choice. 

The largest permanent venue seats a mere 2.500-3.000 spectators and does not come close to satisfying the needs of accommodating the swimmers competing and their close family. 

Friends, fans and the like would have zero chance of a buying a ticket to watch.

There are of course some major obstacles to overcome in order to be successful, both logistically and financially. 

You need partners who can provide a suitable venue in a timeframe that doesn’t bankrupt the Organising Committee because of venue rental, which is the major cost in the financial equation. 

It is not just the period of the event to consider, but the time to build and dismantle as well as the need of practise time or even test events. A six-day rental easily moves to a minimum one month. 

The main reason that this is now possible for swimming events is the use of modular pools and the fact that Myrtha Pools (a small pool specialist company in Northern Italy) uses this technology to build permanent pools. 

Lani Cabrera, former Olympic swimmer in Rio 2016 and Myrtha brand manager, explained: "As a former competitive swimmer, championships hosted in a Myrtha pool always had that enticing aspect, being that they were, and still are, known within the swimming community as fast pools." 

"The innovation of Myrtha Pools giving the opportunities to swim in world-renowned arenas and sporting venues around the world, really changed the game for aquatic athletes, and aquatic sports."

A total of 168 world records have been set in Myrtha Pools but they set world records themselves by building two 25 metre pools in in six days for the 2004 World Short Course Championships in the Gainbridge Fieldhouse, Indianapolis, home of the Indiana Pacers. 

In 2016 Myrtha built two 50m pools for the US trials in Omaha in 14 days.

These timeframes include setting foundations building the structures, the filtration, mechanical and water treatment facilities, installing miles of piping and filling with 7,7 million litres of water (1,7 million gallons in the US trials 2021). 

The pools have to be ready for training in this timeframe so the water must be heated and treated, and the course must meet stringent measurement standards for qualification and record purposes. 

The pool in effect is built to a permanent international standard. One of the brilliant consequences after the event, coming as a result of an Organising Committee choosing to build a "temporary" pool, is that a final client will benefit by installing the same pool permanently, leaving a lasting legacy. 

An approach that promotes the growth of aquatic sports movement in the local communities.

The seven temporary pools used in London were donated by the Government to several different municipalities and schools where they are permanently installed. 

Recently Las Vegas, Abu Dhabi, Omaha, Tokyo, Split, and Fukuoka have followed that suit, and Paris have plans to do the same. Governments also avoid the ongoing costs of operating or finding a suitable partner to operate these mega facilities. 

The London Aquatics Centre is now operated by GLL who pay a nominal leasing fee in return for making the facility available at suitable cost to both the general public and the competitive community. 

They have done an outstanding job for the community but as the facility now only permanently seats 2,500 with capacity for another 1,000 temporary seats, it means that London would need a temporary venue in order to host swimming at a World Aquatics Championships.

Myrtha's modular stainless-steel technology plays a pivotal role in making this transition successful. 

Not only does it offer cost-effective solutions, but it also ensures that the pools are compliant with international standards.