The opportunities arise from the fact that shipwrecks and other underwater sites in the Great Lakes are often well preserved by the cold fresh water in which the are found. Working underwater, however, poses special challenges. One of the biggest difficulties is that communication is awkward. We can't just talk casually to each other under water, so we have to carefully plan what we're going to do before we dive. Mostly, we just try to prepare well, and write notes to each other when we have to.
Visibility can be another problem.
Sometimes it's limited to only a few feet. This makes sketching, note taking, and other documentation underwater very difficult. Photography and videoography are also complicated the underwater environment. It is impossible to see the entire wreck at once. Here is a site map of the Frank O'Connor , another wreck near Door County.