Repeated freediving – An efficient and safe method to rescue subjects trapped in cars underwater

Publication date: October 2019Source: Safety Science, Volume 118Author(s): Erika Schagatay, Pontus Albertsson ÅmanAbstractA method based on repeated freediving was developed to rescue subjects trapped in cars underwater – a scenario leading to 5–6 annual deaths in Sweden, and thousands globally. We determined rescue time and whether the divers were at risk of hypoxic blackout. Cars containing 5 kg negatively buoyant rescue-dummies strapped with seatbelts were placed on 5 m and 8 m depth. Eight freediving-instructors made 230 freedives, working in pairs with one diver always at the surface. For each rescue, two freedivers, equipped with mask, snorkel, fins, weight-belt, wetsuit and a buoy with belt-cutter and glass-breaker freedived alternating in turns between the divers. They accomplished a maximum of one of the following tasks per dive; (1) Finding the car; (2) Marking car with buoy; (3) Opening door/crushing window. (4) Opening/cutting belt; (5) Retrieving dummy to surface; (6) Transporting dummy to shore. Dummies were retrieved to shore from 5 m depth within a mean (SD) duration of 4 min 16 s (1 min 36 s) and from 8 m within 6 min 22 s (2 min 13 s; P < 0.05). Mean dive duration was 28(7)s (14–46 s), with 3 dives over 40 s duration. Freedivers arterial oxygen saturation (SaO2) levels were measured in dives of 30, 35, 40 and 45 s using pulse oximetry. Mean (SD) SaO2 at 20 s after surfacing was 90% for 45 s dives. This allows rapid recovery a...
Source: Safety Science - Category: Occupational Health Source Type: research