Vessel #1 was traveling at no-wake speed towards Lake Michigan. Approximately 40 minutes into the journey, an explosion occurred in teh engine compartment, disabling the engine of teh boat.  Before explosion operator used bilge pump twice without problem. After explosion, aksed all occupants to go down and get life jackets (children were already wearing them )  Operator then dropped anchor for avacuation.  
Deputy said later it appeared to be a gas vapor explosion.
Two people (one female 63, and one child of 3) had flash burns, but treated it at home.  No hospital or doctor was involved.
City of South Haven           