The cold shock is only slightly allayed by the wetsuit clinging to my body as I jump off the metal steps into the frigid ocean, but the pleasure of it trumps the pain. I take a few jagged breaths through my snorkel and feel my muscles immediately tighten as the blood in my limbs rushes from my extremities to my core. A shiver works its way from the base of my neck down my spine. There’s a splash behind me as Madhavi jumps in.

I fin hard through a school of black-and-white-striped mado hanging out in the rocky shallows, until I reach the middle of Clovelly Bay, protected from the open ocean by a submerged rock wall at its mouth—the remains of a failed attempt to build a causeway across it in the 1930s. I pause to prepare, to acclimatise: I remove my snorkel from my mouth, then roll onto my back, close my eyes and breathe deeply, letting myself be cradled and gently rocked by the sea. Three lead weights are strapped around my waist but my rubbery second skin helps me stay afloat.