Devil's Breath Volcano (Macgregor Family Adventure Series)

This fifth novel in the series finds the MacGregor clan stumbling into yet another adventure of danger and intrigue. Chris, R.O., Heather, and Natalie are kneedeep in mystery after discovering the hidden chamber of a sunken vessel. As the story unfolds they find themselves, along with World War II veterans, fighting greedy men whose actions have led to environmental damage.