Guaranteeing to catch fish is a hard thing to do. So this is what I came up with.

"I guarantee that you will have a great fishing experience on Lake Erie."

"I guarantee you that if we do not catch one legal fish by the time your trip is over, I will refund half your money back.  That's right. No fish, half your money back!"

E-mail me for more details...
Captain Frank:
ftberry23@yahoo.com