I have to agree with GFC about keeping a knife sharp is alot easiar and better than sharpening one,when it comes to filet knives and chefs knifes.I just bought a new set of J.A Henkels and just touch them up with the steel and love them.

I have fillet thousands of fish up north with one Victornox fillet knife and never did any thing but touch it up with a steel.The problem with stones and fillet knifes is that if they are used wrong they scratch the sides of the blade adding friction during the filleting.I never let anybody else use it and took care of it for years.When I quit working up north I brought it out to use in the kitchen and my wife had it ruined in a short month by tossing it around in a ceramic sink.Now I beat her over the head with a rolling pin if she does not simply rinse and wipe my new knives off and put them away.

For my buck knives and such I have a couple of old stones handed down from Gpa,work great with a little practice and patience.