The collision happened in Lake Mälaren in central Sweden, near Ljunglöfska castle. A 46-year old woman swimming near the shore received serious head injuries by a jet ski, despite a law against riding one of these fast water craft outside of the permitted lanes.
On Wednesday the Agency for Marine and Water Management will have to come up with how much responsibility jet ski riders must have for the safety of those around them.
The current law from 1993 says that jet skis need to keep to the public water-lanes, but this conflicts with EU rules and so it is impossible to sentence anyone for breaking the jet ski laws, reports news agency TT.
Maritime police officer Fredrik Josefsson says that the current rules need to be scrapped and jet ski riders need to be simply covered by current safety laws, plus an age limit and license to ride a jet ski.