Available for all
The NSS-CDS has made Sheck Exley's 'Basic Cave Diving: A Blueprint for Survival' available for free to download.
Source:
Exley's 'Blueprint' Available for Free
The NSS-CDS has made Sheck Exley's 'Basic Cave Diving: A Blueprint for Survival' available for free to download.
Source:
Exley's 'Blueprint' Available for Free