According to a Jacuzzi, Inc press release "The History of the Jacuzzi Brand": ...begins in the early 1900s, when the seven Jacuzzi brothers immigrated to California from Italy.

The brothers made great strides in aviation by inventing the first enclosed cabin monoplane, which carried mail for the U.S. Postal Service as well as passengers from the San Francisco Bay Area to Yosemite National Park in California.

Incorporating their hydraulic insight, Jacuzzi Brothers, as they'd come to be known in 1920, later made notable advancements in the agricultural pump industry, which led to an invention that remains an iconic fixture in American homes today.

Since then of course there have been many further developments and the Jets design has increased very considerably.

There is no doubt in my mind that that back in time just over half a century ago (1954) when the Jacuzzi brothers Invented a portable whirlpool pump (simply as I understand it because one of their relatives had arthritis) that they would not have had an inkling that this would go on to form such a large and developing industry.

Hot Tubs are now being made in most western countries to the highest standards and the development of the product continues at a pace. The original Jacuzzi pump, when coupled with jets using an air-injection system, a mixture very similar to a kind of bubbly water-and-air was created. With the natural passing of time, a variety of American manufacturers experimented with methods to propel the air/water stream into the spa with ever increasing digress of pressure and control. Initially spas used a simple idea that involved something like a vacuum cleaner motor but operating as a blower in some ways similar to blowing air into the hot tub in exactly the same way that we as children would have used a straw to blow bubbles in to a glass of lemonade or coca cola.

Again as time passed the designers soon began thinking of things like the venturi principle, in which water is pumped through a funnel-like device to create a vacuum that pulls in air. As the water flow and pressure increases, the jet automatically draws in more air, which results in more water flow and movement not unlike the idea of an exhaust driven turbo charger in a car.

Many modern Hot Tubs have the ability to bleed air into so that one is able to inject air into the Jets thereby increasing the pressure and movement of the water. Not unlike perhaps a turbo charger on a car.

The pioneering spirit of the original Jacuzzi brothers was alive and well in third generation family member Roy Jacuzzi, who invented the world's first whirlpool bath in 1968. As a teenager, he started working in the family business in a variety of odd jobs, really learning how the business worked from the ground up. In 1968, his passion for design and engineering emerged when he invented and marketed the world's first fully integrated whirlpool bath, known as the Roman. Sensing that American consumers were moving toward an emphasis on health, fitness and leisure activities, the determined Jacuzzi peddled his invention one at a time at county fairs and trade shows in California.

At the same time his family members looked on with both surprise and delight, Roy slowly – and more or less on his own – created a brand new industry.

Quoting Roy Jacuzzi, chairman, CEO and president of Jacuzzi Inc. of California USA Roy said "A venturi system is a conventional approach," "What I did was take air and water all around that so I was getting a 300/60 air-to-water mixture. "I was actually taking the water and air combination ... and exploding that," he added.

The earliest spas, though, incorporated only enough jets to churn the water.

Quoting another Spa manufacturer Bernie Burba, founder of Baja Products Inc in Tucson, Arizona said "When we first came out with spas, they had two spa jets on them, "Now you see portable spas with 60 on them. You might say that's overkill, but it isn't," he said. "We've really learned about water therapy and that lots of jets - lots of water and air moving across your body - is a very satisfying, restful and helpful experience."

Today, the jets of a Hot tub provide pulsating and soothing massage action all over the body, from stiff necks to sore feet. Hot Tub & Jacuzzi style Spa manufacturers now offer various specific jets to help massage the neck and shoulders, arms, wrists, hips and thighs, the knees, calves and feet etc.

Apart from the original idea of being able to combine warm water and air to create the Spa effect there is no part of a Hot Tub that has not had improvements and amendments made to technology and indeed the construction and manufacturing processes used in making a Hot Tub.

Whole industries have been spawned producing the components and raw materials that Hot Tub manufactures require. The Acrylic Sheets that form the Shell the electronic controls the pumps and motors. Each and every American Hot Tub manufacturer has tried to be at the cutting edge when introducing new ideas.

To summarize it pays to buy a product from a leading American or Western manufacturer as clearly they have been at the forefront of developments in this industry for more thsn 40 year and not a cheap import from China no matter how well it is disguised or packaged.