Objective To investigate whether the Victorian mandatory personal flotation device wearing regulations that came into effect on 1 December 2005 reduced drowning deaths among recreational boaters in Victoria, Australia.

Design A retrospective population-based ‘before and after’ study using Victorian coronial data on drowning deaths of occupants of recreational vessels operating in Victorian waters.

Methods The annual numbers of deaths in the 5 years after the transition year of the regulations (2005) was compared with the annual numbers of deaths in the 6 years prior to the transition year, using the Mann-Whitney U test.

Results There were 59 recreational boating drowning deaths in the 6-year preintervention period (1 December 1998 to 30 November 2004) compared with 16 in the 5-year postintervention period (1 December 2005 to 30 November 2010). The analysis showed a significant decrease in drowning deaths among all recreational boaters (U=30.0, p=0.01) and among these strata: vessel occupants aged 0–29 years (U=28.0, p=0.02) and 30–59 years (U=27.5, p=0.02), vessel occupants engaged in pleasure cruising (U=29.0, p=0.01) and in ‘other’ boating activities (U=25.0, p=0.04), boaters on small powerboats ≤4.8 m in length (U=29.5; p=0.01), boaters on motorised (U=29.5; p=0.01) and sail-powered vessels (U=26.0; p=0.04), and occupants of vessels operating in inland waterways (U=30.0; p=0.01).

Conclusions These findings provide further support for the adoption of a regulatory approach to personal flotation device wearing to reduce drowning among recreational boaters.