Now that I haven't seen a "way-around" other than actually performing the dives yourself and discovering them, or by downloading a save where that step has already been completed.
Maybe someone around here with more Black Flag gaming experience than myself could better answer that ?
JJavierMendoza
after further googling I have yet to find a way to get the elite upgrades other than diving the dive on your own. Just keep trying, after a few try's you should be able to find the correct chest and get the upgrade plan you are after.