City Sailingvideo

The Thames' Deadliest Secret | Cold Water Shock

February 17, 2021 · 7 min · 5K views

What this video covers

The Thames presents significant hazards to swimmers and boaters, primarily due to cold water shock, fast-moving tides, and dangerous undercurrents.1:37 Cold water shock triggers an involuntary, immediate gasp reflex and hyperventilation, which can lead to drowning after inhaling as little as two to three pints of water.5:26 Even strong swimmers lose the ability to control their breathing or perform basic survival tasks within seconds of immersion.5:46 Beyond the immediate physiological response, the river’s strong currents and eddies frequently trap individuals under pontoons or sweep them away from the shore.0:54 Historical incidents, such as the 1989 Marchioness disaster involving the aggregate carrier Bowbell, highlight the risks of navigation and visibility on the river.0:12 Emergency services, including the RNLI and Port of London Authority, emphasize that if a person falls into the water, the most effective survival strategy is to float, remain calm for 60 to 90 seconds, and keep the airway clear until the initial panic subsides.6:33

Watch on YouTube

More from City Sailing

Teamwork on the Water: Isle of Dogs at the Sea Cadet National Championships 26Sep 2026RS Tera Eastern Championships: What Went Wrong at the Start?Sep 2026Isle of Dogs Sea Cadets return to city race training Sept 26Sep 2026Epic Urban Sailing with the Isle of Dogs Sea CadetsSep 2026

From City Sailing — see the channel’s boat, crew, and every analyzed video.

The Sailing Directory Newsletter

One email with the fleet's best finds — the moments, boats, and stories worth your watch time. Enter your own address to get your own copy.

Report an issue