When I ran long auto line for coon I used a lot of pockets in ditches and creeks. I have all ny 5 and 6 foot drowners made up with the top stake attached. The top stake is wood with a 4'' pigtail of wire ran through a hole in the stake about 2'' down from the top. Wood stake are hard to get out so the wire lets you get the drowner off easy. I use wood on the deep stake too. Use a 2 x 2 piece and put extra wire on it so you can wire a drowner to it. You can use RR plates. Old Wheel Rims, Concrete, re-rod, fence posts, what ever. It doesn't matter just so it is either heavy or staked to hold a beaver and you'll be fine. Also found that if I use a tall stake sometimes a coon will wrap around it and pull out so do not leave a stake sticking up so something can wrap around it. Always give them nothing to pull against and keep them swimming like TONY said.
Sometimes at plunge pools you can have several sets across from each other and run wire or cable all the way across the creek to the next set. You don't need a deep stake for this type of trapping. Just twist a small piece of wire on the cable or wire where you want the trap to stop in deep water. Make sure the trap chains cannot cross in deep water or that will be trouble too . Keep your catch far enough away from each other so they cant fight.