I've been trying to track down the details of this particular issue, actually. As far as I can tell, it was offered for sale by IGN.com (for $7.99 or as part of an IGNsider premium subscription) but also looks to have been distributed to GameShark Magazine subscribers.
More details here:
https://community.retromags.com/topic/10426-missing-magazine-dangerous-watersgameshark-magazine/