Progressive penetration is his preferred approach under water, exploring a little further inside a wreck on each visit and really getting to know his way around before moving deeper inside.
Whether on a shipwreck or in a library, Petkovic is clearly one patient diver, but seemingly someone to trust.
Lake Erie might not be on your to-do list, but for those seeking new wreck-diving challenges it could be interesting. The author covers 19 wrecks here, divided into Deep, Tech and Trimix (beyond 56m).
Some, like the paddle-steamer Atlantic, merit 21 pages of history – much of it, in this case, about the fascinating 19th-century salvage operations – and half a page on how to dive it. Others, including a number that are unidentified, are all diving.
The writing is clear and descriptive, factfiles and safety tips are helpful and there are quite a few greenish underwater photos and illustrations. Nice cover too. Up for something new?