Go to any chandlery in France, Spain, Italy, or the UK and you're likely to find fully rigged handlines for sale not unlike this one...
Just the thing to troll behind your sailboat and catch fish with.
What's not to love? They're cheap at around $20, effective, and don't take up a lot of space on the boat,
Of course if you go to West Marine or some other American chandlery you're most likely to be confronted with something like this which, while it happens to be a fairly nice rod and reel combo, is not well suited for use aboard a sailboat and by the time you've bought all the required gear to make it work it will cost you right around $300 and it would still be the wrong tool for the job at hand.
So why doesn't West and other chandleries sell handlines?