Attached are a couple of my photos of the Trail.

That is a fantastic story.  I've been by the mangrove swamps but I never dared to venture into them.  Your dad is quite a guy!

Grande Tours, Placida, Florida is mentioned in the article.  They are within a mile of these trails and are a full service kayak touring, sales, guided trips company.  They are on the web.  There are several good sized coastal islands adjacent:  Boca Grande, Little Gasparilla, Don Pedro.  Also Cayo Costa, a state park on an island with primitive camping and also some roofed, 3 sided huts with floors right on the Gulf beach and not very busy.  I am sure you can google any of these spots for lots of information and more photos.  Good fishing, tons of birds to watch, generally good weather although sometimes windy.  One advantage of the mangrove trails and lagoons is you can enjoy them even in windy weather and it is shady and cool under the trees on hot days. 
You might see Bobcats, Racoon, Ferral Hogs, Otters, ducks, loons, Pelicans, Roseatte Spoonbills, Wood Storks, 6 kinds of large to small Herons, Gulls, Cormorants, Eagles, Ospreys,  Cardinals, Magpies, and in the water: crabs, living shells, oysters, Mangrove crabs, Sting Rays, Manatees, schools of Mullet, and lots more.