Ive done it with just the spool with my compound. My brother is from upstate new and he uses my old like 40 ilb bow and they shoot huge ones up on ontario. I do my spearing in the creeks in chambersburg and i use a gig i got that used for flounder. Its great trying to sneak up on them.
my buddy uses his old browning set way down to around 50 i beleive. he bought the spooling kit at gander ive watched him do it hes a good shot above water but in 2 years he still hasnt connected with one that swims maybe 20 shots attemped
They have come out with a laser that makes aiming a little easier. The laser doesn't "bend" underwater. Normal sighting requires you to aim lower than the target. I'm not sure it would be legal in Pa. though. There are a few youth crossbows in the 40 lb. range that should work for fishing.