The blast killed an American and injured nine people. He said both of his sisters, Stefanie and Brooke, were on the boat with their mother and stepfather Stacey and Paul Bender.
Schaffer also suffered broken arms, a fractured spine and internal injuries, The Rutland Herald reported. Their mother also reportedly sustained several broken bones and a lung contusion.
Four of the injured people were moved to Clearwater, Fla., hospital by the U.S. Coast Guard.
Girl who died in inflatable trampoline incident was at beach with mother
In an incident which started as fun and ended as a tragedy, a young girl died after a bouncy castle on a beach exploded. Bouncy castles should be temporarily banned in public areas after the death of a child in Norfolk, an MP has said.
The incident happened on Saturday morning in the waters of Exuma Cays and involved a 4C's Adventures charter boat with around ten people on board.
Chaffer has been in a coma since the accident with a brain injury and has undergone five hours of surgery, including having parts of her legs amputated.
"I wouldn't leave Stefanie's side", Sheila Jones said, "because all I could think about if that was my child I would want someone there".
The page had raised more than $43,000 for Tiran Jackson's medical and travel expenses as of Tuesday afternoon.
The family said in a statement to USA media on Tuesday: "As you can imagine this is an incredibly hard time for the family, especially Tiran and Maleka's 12-year-old son". Sheila Jones and John Inman were named as other passengers on the boat, but they did not suffer serious injuries. The cause of the explosion has not been determined at this time. "We are saddened and our hearts are hurting, but we will get through this together", Cooper said in a Facebook post.