"Mark the Spot" joke

Year after year Bubba's wife pleaded with him
to take her fishing but he kept telling her
she would not enjoy it. She, finally, wore him
down, he consented, and early one morning they
took off to the lake.
They had not been there very long when the fish
began biting. Almost as fast as they cast, a
fish would bite, and they reeled it in. After
catching their limit, Bubba said,
"Martha, sweet thang, I'm sorry. You've been good
luck and I'm gonna bring you with me the next time.
If you'll mark the spot where we caught all these
fish, we'll go home."
On the way home, Bubba turned to Verna Lou and said,
"Sweet thang, how did you mark the spot were all
the fish are so next time I'll know?"
"Bubba, darlin', I put a big 'X' on the side of
the boat right down closest to the water."
"Sweet thang, that's about the dumbest thing I ever
seed you do. Don't you know that won't work? We
may not get the same boat the next time!"