Background Diving related injuries are often catastrophic and result in life altering effects for victims and their families. One common approach to alerting people to diving hazards and injury risks is through the posting of warning signs. Of course, whether warning signs are effective for these purposes depends in part on how well viewers understand the intended message. The current study examined children’s understanding of various features of No Diving warning signs.

Methods Normally developing 7 to 10 year olds were asked questions to assess their understanding of text, images, and main messages on No Diving warning signs. These structured interviews were audio recorded and responses were later coded, with excellent resulting reliability (Kappa = 0.91).

Results Children understood the behaviour advised against (diving), why it is prohibited (can hit head on the bottom), and what can happen (serious injury including hospitalisation). They understood that breaking your neck results in limitations in mobility and can occur from diving, but they did not anticipate that such an injury is likely to occur. There were no gender and few age differences, but diving experience was associated with children significantly downplaying their risk of injury.

Conclusions Having No Diving warning signs explicitly mention a broken neck, may serve to remind children of this potential consequences at the time of decision making. Active adult supervision is particularly important for children who have prior positive diving experiences.