Late onset of decompression illness (DCI)

  • Safety Flash
  • Published on 1 May 2004
  • Generated on 30 August 2025
  • IMCA SF 04/04
  • 2 minute read

IMCA has received a safety notice which provides a good reminder on the subject of decompression illness (DCI).

What happened?

A company has reported that, following an air dive, a diver developed a pain in his arm more than seven hours after decompression. Due to the length of time between the dive and the complaint appearing, it was assumed not to be diving related and painkiller medicine was administered. On worsening, two hours later, the diver was recompressed, but his condition did not markedly improve. It is believed that the period of non-recompression allowed the gas bubble(s) in his tissues to expand and cause internal lesions before dissipating. Thus the later therapeutic treatments, designed to dissolve the offending ‘bubbles’, were unsuccessful, as they could not provide relief for existing physical lesions.

The company has reminded its personnel that whenever a diver reports complaints which appear consistent with type I and/or type II symptoms, even up to 48 hours following an air or nitrox dive, the divers must be recompressed immediately, in accordance with company DCI treatment procedures. This should take place immediately – before or in parallel with contacting the diving doctor. If the case is DCI, correct action will have been taken. If it is not a DCI, therapeutic recompression will not make things worse.

Latest Safety Flashes:

UK HSE: Motion Compensated Gangways Auto-Retraction

The UK Health and Safety Executive (HSE) has published Safety Notice ED03-2025

Read more
Brazil: diver permanently disabled after decompression illness

Conviction of diving company upheld as work accident suffered by a diver who lost strength in his upper limbs and the ability to move, requiring permanent use of a wheelchair.

Read more
Diver reports unwell post-dive: non-decompression illness

A diver experienced a dizzy spell about one hour after completing a diving operation

Read more
Shore-side crane boom collides with vessel mast

During shipyard lifting operations, the boom of a dock crane made contact with the vessel mast.

Read more
Injury sustained while operating steel lifting magnet

While preparing to transfer steel plates using a steel lifting magnet, a crew person was injured.

Read more

IMCA Safety Flashes summarise key safety matters and incidents, allowing lessons to be more easily learnt for the benefit of the entire offshore industry.

The effectiveness of the IMCA Safety Flash system depends on the industry sharing information and so avoiding repeat incidents. Incidents are classified according to IOGP's Life Saving Rules.

All information is anonymised or sanitised, as appropriate, and warnings for graphic content included where possible.

IMCA makes every effort to ensure both the accuracy and reliability of the information shared, but is not be liable for any guidance and/or recommendation and/or statement herein contained.

The information contained in this document does not fulfil or replace any individual's or Member's legal, regulatory or other duties or obligations in respect of their operations. Individuals and Members remain solely responsible for the safe, lawful and proper conduct of their operations.

Share your safety incidents with IMCA online. Sign-up to receive Safety Flashes straight to your email.