If I can freedive on one breath to over 40 metres, how deep can can I dive with Scuba gear? Would breathing compressed air at 40 metres have an effect on me (nitrogen narcosis, for example)?
The Aiona is a wreck in the Red Sea. The story I was told is that the ship was captured from the British by German submariners in World War 2. The Germans gifted it to their Turkish allies who ran it onto a reef off the coast of Yanbu, Saudi Arabia and it’s been there ever since!
I’ve explored between 35 and 40 metres deep a number of times on this particular dive site and become familiar with it.
Here is a video of an earlier trip:
This 40s 4 40 trip, I was with a number of very experienced divers, none more so than my buddy. We wanted to know how deep the sea bed is and so took measurements in the sand, a few meters out from the propeller. Previously, I had only ever hovered above the sea bed, toward the top of the propeller.
By doing so we achieved a depth of 48.7 metres – that’s my deepest dive so far.
Diver above the starboard side of the propeller 
Diver going through the starboard side of the propeller 
A few metres from the propeller 
My buddy depth checking the sea bed 
The Port side of the propeller
Even though I was only 5 minutes into my dive, you can see from the below data how little time was available at that depth before I had to ascend to a more shallow depth to stay within no decompression dive limits (<2 minutes):
Clearly, I was aware of this and started to ascend too quickly for the dive computer’s liking; I was only 8 minutes into my dive and already on my ascent but within one minute of no decompression time!
Once I had added a few more minutes on my no decompression time by ascending, I slowed my assent rate appropriately.
The rest of the dive was spent at a more shallow depth exploring the wreck itself and the reef to the North of it, before returning to the dive boat. The brief dip during the safety stop was to retrieve something.
Going beyond no decompression limits is not necessarily a problem provided you manage it correctly but I believe it is good practice to stay within no decompression limits when recreational diving unless exceptional circumstances and experience provide good enough reason to go beyond them (e.g. an emergency or something like a specific wreck or incredible marine life).
I experienced no negative effects during or after this dive. I’m left with a recollection of feeling lonely down there and it clearly being time to get back to the surface (full Buddy respect).
Suffice to say, it is of the utmost importance to always dive within your personal limits, relative to your qualifications and who you are with.
Here are some pictures of the Aiona from an earlier trip:
Being reasonably familiar with the Aiona and with the support of my friends and dive operator, I freedived the wreck. The highlight for me was penetrating the wreck through a hatch on the port side and swimming up through the hull of the wreck before exiting through its broken deck to re-surface.
You can watch more about the Aiona in the amazing documentary ‘Desert Seas’ by David Attenborough:
