Fig. 1

Study flow. Members of the International Life Saving Federation (ILS) Medical Committee (ILS-MC), the ILS Rescue Commission (ILS-RC), and the International Drowning Researchers’ Alliance (IDRA) with a background in clinical health care as a medical doctor, nurse, paramedic/EMT or similar were eligible for inclusion as potential experts. The inclusion criteria included at least one of the following three criteria: (1) Having clinical expertise in handling patients with suspected in-water TSCI, (2) Having teaching expertise in handling patients with suspected in-water TSCI, and (3) Having research expertise on in-water TSCI. The study was initiated in October 2022, concluded in November 2023, and consisted of three Delphi rounds. In Delphi round two, the level of agreement for each recommendation and the flowchart was calculated as the frequency of “agree” (3) and “strongly agree” (4) on a 4-point Likert-like scale and divided into three levels: (1) recommendations with strong consensus (≥ 85% agreement) underwent minor revisions and entered round three, (2) recommendations with moderate consensus (75–85% agreement) underwent major revisions and repeated round two, (3) recommendations with weak consensus (< 75% agreement) were excluded. In Delphi round 3, the level of consensus for each of the final recommendations and each of the routes in the flowchart was tested using the same procedure as in Delphi round 2. The consensus threshold was an agreement of ≥ 75% among the experts