The Kastboj was created in a project which aimed at finding alternative product solutions for life saving in water. A thorough user study was conducted where people with experience in life saving at sea (professional life savers and maritime personnel) along with everyday people were interviewed. Identified needs were translated into following product requirements:

The product had to be mobile, have a high usability, an intuitive design and be able to reach and transport a person in distress.

Using the requirements an iterative design process containing ideation, prototyping and testing was performed before deciding on the final concept: Kastboj.