As I luxuriate in the glass-sided pool, a guy gets dressed for the day in a pair of raggedy trousers. At the same moment, an elegant woman in a nightgown opens the curtains to her hotel room above. She is in white; his outfit is more the colour of charcoal.
I knew these huge inequalities existed in India but on a second visit it's no less confronting.
According to our previous day's tour guide Vinita, the caste system is alive and well, the untouchables or dalits still tasked with the job of cleaning streets and toilets.
At the other end of the spectrum, the upper caste Brahmin families are still on the hunt to marry off their children to the wealthiest spouse. They may have toned down the language they use in the arranged marriage ads in the newspaper, but the position they occupy in the social strata is no less clear.
Pale skin is a mark of belonging to the higher castes, and Vinita says the ads for potential brides in The Times of India used to call for "convent-educated, fair-skinned girls".
Now, she says it is "a girl of good family for a handsome groom". "The groom is always handsome," she jokes.
After my swim, we spend the morning visiting Mumbai's fruit market with kiwifruit company Zespri's India team, an experience I'll write about in Saturday's paper. Kiwifruit is growing in popularity in India and Zespri is using a Bollywood child star to teach consumers how to eat the fruit.
I have loved our time in the crazy city of Mumbai and only wish it could be longer, but this afternoon, we are leaving the country's financial hub and flying into its political heart.
We board an Air India flight to Delhi and take another drive through India's mad traffic in the capital. The jams we experience in India put our holdups of a few minutes in Tauranga into perspective.
We arrive at our hotel, the regal old Vivanta by Taj Ambassador, a white stucco building built by the British as a cluster of residences.
The rooms each have their own lounge, the whirring ceiling fans and drawstring curtains completing the picture in my mind of some British toff and his wife ordering up a tray of tea and cucumber sandwiches.
It's a far cry from edgy Mumbai and its glass-sided swimming pools.