Pat Quirk of Guelph, Ontario, bought a $25,000 extreme-terrain vehicle that he could use both on land and in floodwaters to help her sister living in Houston.
His old buddy Bill Hamilton, a landscaper, joined him in the cause.
They both loaded the extreme-terrain vehicle in the back of a pickup truck on Monday and drove across five states in 24 hours, arriving on Tuesday.
Quirk found his sister safe in a hotel but the damage to her home was extensive.
But Quirk found another use for the extreme-terrain vehicle, rescuing others still trapped by the flood waters.The best friends had already rescued at least a dozen people as of Friday.