Legend of Firefly Marsh (1987)

Firefly Marsh is a fog-enshrouded corner of the world, steeped in mystery. Stories of what lurks in the dark waters date back to Indian lore. But could Firefly Marsh really hide a prehistoric creature like the one in Loch Ness? Twelve year-old Charlie Curtis and his friend Jim may have found the answer after "something" swamps their dingy in the marsh. Was it the monster? For Charlie, that night sparks a personal odyssey that will take over half a century to finish. The memory of what he saw becomes his obsession, his lifelong passion. When Charlie's grandson, Kevin, comes to visit for the summer, he becomes caught up in his grandfather's stories. Are Charlie's stories just to entertain the local children or is there some truth to the old man's tale? Soon the curious teenager begins his own adventure, a quest to solve the mystery behind The Legend of Firefly Marsh. - Written by Gabe Torres

Unfortunately the movie Legend of Firefly Marsh is not yet available on HBO Max.