I have no idea if the photo is fake but it has been making the rounds on the internet over the weekend. If it's a fake they did do a good job putting all the pieces together including the small collage of memory photos of grandpa out kayaking.
The forum on Reddit is all abuzz if bad and goofy puns. Here is a brief sample:
"At least the funeral seemed to go swimmingly."
"Making jokes at a funeral, canoe believe this guy? That is definitely a paddling."
"Give him a stern look and thwart his plans."
"I think we should all take a bow for our efforts."