They make Jets in 20', 30', 40' and 50' I believe. I run 30' jets and never let them out 100', I adjust accordingly. They're a tool, like dipsy's...lol
I would think the tadpole divers would be good up until you toss a deep diving crank on one..?
I use jet divers off of inline boards with shallow running (5' to 8') hard plastics for mid to late summer walleyes. I have no experience with the tadpoles, if that helps at all.
It was an annual spring thing when I was a youngster but we use steel dip nets in the rivers and creeks, and yes as I aged beer was a must. Hard to beat a smelt dinner..