She will patrol the water. A roaming cat treats a pool edge as a path, a hot tub rim as a lookout, and any cover as ground she has not tested yet. Cats generally dislike swimming, but the accidents this question is really about are falls: a lunge at a bird, a chase that ends at the coping, a misjudged leap in the dark. Precautions built for the fall, not for a cat who means to swim, are the ones that hold up, and they work in layers so no single failure leaves her in deep water with smooth walls on every side.
The Hot Tub Cover Is the First Hazard
A cover protects her only when it is rigid, fully closed and latched, and strong enough to bear her weight without dipping. The dangerous cover is the soft or sagging one: it looks like a warm, solid platform, invites her to walk out onto it, and can fold around her as it gives, trapping her against the water underneath. Pooled rainwater on top makes the trap worse, adding weight and depth where she stands. Check the straps, clips and locking points as part of the garden routine, brush standing water off, and replace a cover that has gone soft, torn or slack rather than trusting it one more season. Lightweight floating blankets and solar covers are not protection at all; they offer no support and can wrap a struggling cat, so never count them as a barrier. When the tub is in use, she is shut out of that part of the garden until the cover is back on and secured.
A Way Out of the Pool She Can Use
Fencing reduces falls; an exit defeats them. Smooth pool walls give wet claws nothing, so she needs a route she can reach while panicking: built-in steps she can swim to, or a firmly fixed ramp with a rough, grippy surface set at a shallow angle in a corner. Show her the route while she is dry and calm, from the edge, so the corner with the ramp becomes a place she knows. Keep the water level high enough that the top step or ramp stays within her reach rather than a long stretch below the coping. A gate in the fence should close and latch itself, because the gate left ajar by a visitor is the gap every other precaution assumes away. At night and during parties, when falls are likelier and nobody is watching the water, keeping her indoors removes the risk entirely for those hours.
Chemicals, Storage and the Wider Garden
Pool chemicals are poisons in concentrated form, so store them locked in a shed or cabinet she cannot enter, never in open tubs beside the pump where she drinks or grooms. Rinse deck areas where concentrates have been mixed or spilled, and keep test kits and tablets out of the open for the same reason. Walk the boundary as she sees it: gaps under gates, loose fence panels and sheds left open are her map of the garden, and closing them keeps every water precaution on the inside of a fence she stays within. If you ever find her wet, shivering or coughing after time near the pool, treat it as an emergency and phone your vet at once, because water inhaled quietly can worsen after the event. Prevention stays the real protection here; the alert is only the safety net, and Lost Pet Alert System through KinsLe puts word out to owners nearby and opens a direct message from whoever finds her.