I tend to agree with the standpoint that artifacts should stay "in situ" unless they are being removed to be preserved and put on PUBLIC display.
That being said, I also feel that the secrecy surrounding the co-ordinates of the lesser known wrecks in lake ontario is for no other purpose than to protect the incomes of the charter boat operators that will take divers to those wrecks!
I am not sure what the rules and regulations are on using side-scan in lake ontario, I have been in email contact with both sharky's in st catherines, and the MOE, and have not recieved a definitive answer as yet.
I am planning on doing some surveying on lake ontario from my boat this coming summer, using "forward-looking" sonar rather than side scan, interphase technologies makes it as a navigation aid. And I will be looking for hazards to navigation rather than shipwrecks per-se.
If I were to stumble across a shipwreck, I would immediately contact a larger organization such as SOS or POW to get thier assisatnce in protecting the site.
As such, I cannot see a legal basis for the government regulating the use of a navigational aid (in the same class as radar) But I am actively doing research into it, and will post all results as I get them.
Feel fre to pm me if you have any info or CONSTRUCTIVE discussion. Sparky especially, please contact me, as we may be able to share resources.