Thats complete rubbish. As if the only reason to be curiouse about this stuff is so you can execute the perfect crime. Thats paranoid McCartheyist shpiel to the highest degree.
for one, do you really think someones going to research a crime on a scuba diving forum. Two, most murders are crimes of passion giving the murderer preciouse little time for the forethought of reserching how to comit the perfect murder. Three, if a murder is pre-meditated then really all it would take is a little common sense, and there are loads of books avalable at the library or from book shops, or watching Forensic Files on the discovery channel.
And mostly, if someone was going to do a course on forensic diving techniques to get away with murder, well then its pre-meditated, so its 999,999 times out of every 1,000,000 times (not acurate statistics, just making a point) going to be someone the killer already knows. So its going to look pretty suspiciouse when the police find this out, and then inevitably discover why they had reason to want to kill the victim.
To sugest that discussing forensic techniques is putting people at risk is nieve, and downright stupid. Please stop looking upon everyone who has the slightest bit of intelectual curiosity as suspicious.
If it was so dangerouse to be made public then perhapps someone would have stopped text-books on it being sold on AMAZON!