So we all know aikar prevented "sniping the marlix/momentus from a distance or it will draw you in". But most of us know the momentus/marlix is tping you to them. but there is a possible way to prevent that (needs testing) get a boat, a bow and 3 stacks of arrows, sit in the boat and enjoy! You may be thinking how dose this work..? Well simple, nothing can force tp you out of a boat to the player or in this case a mini boss. Could possibly be a easy fix? Before you get force tped boat breaks? Don't know if it works for mine-carts, not waisting my iron on them.
Hmm, just tried this. I have a momentus hanging around my area, so I boated over towards him. He still tp's me into him while I'm in the boat. No joy. I've had this happen with a Marlix too. I was chasing Marlix across the ocean in a boat and he just tp's me in anyways and breaks the boat. EDIT: I just went back to the site and my boat was sitting on the ground still unbroken XD
It def should not care that you are in a boat. When did you try this? It was bugged and still allowed you to snipe for a while, but recently pushed a fix for that.
. . . yeah . . . I noticed the fix Had a hell of a time trying to snipe that momentus, but I finally trapped him in a pit then killed him off while high on zombie virus. If he wasn't in such close proximity to my wild base I would have given up on him long ago. Momentus can pretty much draw you in from visible distance now, especially if you try to snipe him. Thanks for warning me XD lol