Just wondering what type of cable you are using 1x19 or 7x7 ? It can make a big difference sometimes? Thanks.

1x19 on all snares, from 3/64 to 7/64

10- inch diameter snare of 1X16 diameter 1X19 cable and an adams lock.

Where is a photo of the lock the original poster mentioned : Smoothie Lock

Not sure that I've seen that one.

Teacher mentioned about using a length of extension cable with your snare and having the beaver sitting up on the bank.

I would agree there is something to that and have often had them lying there asleep when I arrived.
Some will be out in the water, bobbin' up and down like a cork.

I didn't read many of the responses but can say the SLIM lock along with the Gregerson's L-4 and Grawe's BULLET lock has taken a good beaver for me personally in snares.
Most trappers body snare beaver, which can and does damage pelts at times, causing a reduced price on a pelt.
This is done by not 'speed loading' a snare and setting the loop far too big.
You can snare a beaver right behind the ears in a 6 " loop if set right.

Now, if it's an ADC job, where you aren't skinning the beaver, it wouldn't matter.
An in-line swivel as close to the lock as possible will prevent a lot of disappointments, IMO.
A swivel on the end of a snare, will offer little, as soon as a beaver wraps around any entanglement.

My personal choice for cable to snare a beaver would be 1X19 -5/64th Korean Select in 1/16th Galvanized with a 600 lb in line barrel swivel and a Slim Lock

I am like others. I have been using the old Thompson snare locks for the last 40 years with 5/64 1x19 cable. It works so why change. I have caught groundhogs to coyote with this set up. Even have taken a few beaver. I also like to keep the hole diameter close to the cable size. I also load my snares and they close fast. Just don't see a reason to change. JMO

I like the thompson locks for wolf-they work very well with a kill spring also-as long as the hole is matched to the cable so they lock solid.