That line about the console quietly handing you garbage is the truest thing I have read all week. It does not care that you meant well, it just gives you undefined and moves on with its day. My question is this: when you finally spotted the capital L, was it because you went back and read your own code line by line, or did you do something like drop a console.log on each variable to see which one was empty? I ask because the trick people always give is "just read it slower," and that never works for me. What actually works is printing the thing I think is broken, and nine times out of ten the variable is fine and the name I typed somewhere else is the problem.

Forty minutes in Hood Canal and you couldn't feel your ears sounds more like a fit problem than a neck dam problem. A properly sized hard hat with a good neck dam keeps water out fine, and plenty of guys dive cold water in them every day without turning into a popsicle. Dropping $1800 on a used band mask because of one bad dive is a lot, and now you've got a heavier rig, more o-rings to babysit, and a mask that's a pain to clear if it floods. Neck dams are simpler, cheaper, and easier to fix on a boat deck with a spare. You probably didn't need the jump, you just needed a better hood and a neck dam that actually sealed.