Safety First! A new way forward for archaeological diving operations

By Antonio Santos

Underwater archaeology is certainly one of the most satisfying and fascinating activities possible to undertake. Those of us who have the opportunity to work on submerged archaeological sites love every second we spend underwater. Nevertheless, we must also remember that this same environment is a fundamentally inappropriate place for humans to work, which is why we are reliant upon specialized breathing, stabilization, monitoring, and protective equipment to do so. And that is why “safety first” is our motto.

In Iberia as much as elsewhere, underwater archaeology is still a relatively new discipline. As such, there is still room for a number of improvements, particularly regarding safety standards during scientific diving operations. Firstly, we must differentiate between recreational diving and scientific diving. Why? When scientific diving operations are conducted for work, risks increase, and as a result, so do liabilities. Right now, ForSEAdiscovery is the only underwater archaeology project on the Iberian Peninsula being conducted by academic researchers who are also certified commercial divers. From this position, we want to underline how a system of safety standards for diving, such as those proposed by the UK system of HSE, can considerably limit the risks inherent to diving, and avoid or mitigate common issues that can occur during pre- and post-dive operations.

Archaeologists and certified commercial divers Antonio Santos and Adolfo Martins at the Bayonnaise shipwreck, Finisterre.

Archaeologists and certified commercial divers Antonio Santos and Adolfo Martins at the Bayonnaise shipwreck, Finisterre.

The underwater heritage shared both by Portugal and Spain is vast and rich (and very much threatened by the careless activities of treasure hunting). Because we all want to see the continued development of scientific interventions on Iberian submerged sites, the importance of safe and standardized diving operations must be stressed. The results of introducing such standards to the dive team are immediately visible with each dive: reduction of diving and boat accidents, reduced equipment malfunction, improved general well-being of divers, and better results achieved during underwater interventions.

The common safety trespasses observed during sports diving cannot be tolerated in scientific or commercial diving. We have all witnessed close calls (or worse) because of equipment and/or gas negligence: for example, hoses held by duct tape instead of clips, divers not respecting the limit of 50 bar as indicative of time to ascend, diving without a bail-out or pony bottle, dry suits not fully zipped, regulators filled with debris, damaged hoses, cracked masks, failure to inflate jacket or hold mask/regulators when entering the water, weight belt release not kept free, etc. To avoid these scenarios, we believe it to be in the best interest of divers, employers, and projects to adopt a basic process suitable for any diver, not only in Portugal or Spain of course, but in any underwater environment.

Before we leave surface, there are several guidelines to respect, not only because of our own safety, but also to avoid compromising the safety of our colleagues.

1) Being “fit to dive” is priority number one. Any headache, sore throat, stuffy nose, dizziness, or difficulty to equalize must be reported immediately to the supervisor. He/she is the one responsible for the team and the operations being conducted. Any of these or other symptoms of illness could result in an aborted dive, but how much better to stop the dive than to confront serious health ramifications by proceeding anyway? If you do not feel fit to dive, just say it. With the supervisor’s approval, you might even be able to swap schedules with a colleague and dive later, if symptoms disappear.

2) Equipment is another of our top priorities. Maintenance is required after every dive. And nothing works better than the old routine of rinsing with fresh water. However, constant visual and functional checks of serviced cylinders, hoses, regulators, and full-face masks are advised not only before the start of the diving day, but also between dives. You never know when something might have been accidentally or unknowingly damaged that is about to be used by you or one of your teammates.

3) The third priority is that a “tender” is assigned to each diver to assist with getting dressed in. Before being checked by the supervisor, a tender should guarantee that his/her diver is equipped with the following:

  1. Suit on and fully zipped.
  2. Diver recovery harness on.
  3. Weight belt on and release free.
  4. BCD (buoyancy control device) and/or drysuit inflator hoses attached and functioning via the main cylinder.
  5. Tanks are on. There are two first stages: one on the main cylinder and one on the emergency bail-out or pony. If using a full-face mask, hoses from each first stage should connect at a bail-out switch block, which then leads to the full-face mask and allows the diver to switch between cylinders. Another high-pressure hose from the bail-out should have a back-up regulator. Suit and/or BCD inflation should be supplied from the main cylinder. If wearing a half-mask, there should be two regulators, one from each cylinder.
  6. The diver should have one pair of fins, one pair of gloves, one knife, one diving computer, one hood, one SMB (surface marker buoy) and a mask (worn by half-mask divers or kept in pocket for emergencies by full-face divers).
  7. If hard-wire coms are being used (instead of through-water coms) or in cases of strong tides or low visibility, a life line is attached to the harness and held by the tender.

4) Finally, when the tender and diver are both ready for the dive, the supervisor goes through another checklist to ensure that nothing has been forgotten.

  1. Diver is fit to dive.
  2. Harness and BCD are secure.
  3. Air is turned on.
  4. Bail-out switch-block set to main cylinder.
  5. Drysuit and/or BCD direct freed connected and working.
  6. Weight belt release free and diver can find it.
  7. Diver has a knife and can reach it.
  8. Diver has fins, gloves, hood, mask, computer, SMB, and any other equipment necessary for task.
  9. Main cylinder and bail-out test: diver has to switch from main gas to bailout and back via the switch-block.
  10. Diver is secured for entry: if striding, help him/her to stand and hold cylinder until ready; if rolling, ensure water is clear for entry.
  11. Coms check at designated area.

Safe and productive diving!


Antonio Santos is a PhD student at the Instituto de Arqueologia y Paleociências, Universidade Nova de Lisboa.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s