I have gone completely off the rails.

The underwear was bad enough. What I did next was absolutely chilling.

I swam in a lake.

I know! Me! The girl having a nervous breakdown over alligators!

To be clear, I was very worried about alligators each time I swam. I scanned the lake before each dive, looking for reptilian eyes lurking above the surface. I’ve seen Lake Placid. I know how this works.

I’ve also read Close to Shore, the true story Jaws was based upon. That shark made it into a creek. Which I know is very different from a lake. That’s why sharks were low on my list of concerns. It’s not like I was sitting there fretting about the Loch Ness Monster. I’m not ridiculous.

Snakes were higher in my catalog of fears. I don’t know the likelihood of seeing a snake in a lake in Maine when the air temperature is in the seventies and the water temperature is even colder. But I do know you’ll miss it if you don’t look for it. So for the love of all that’s holy, look for the snake.

My priority concern, obviously, was Naegleria fowleri, the brain-eating amoeba. Talk about terrifying. For the next few days, any headache in my house will send me into a tailspin.

With all of these very legitimate concerns, you’d think lake swimming would be on the list of things I never do – like skipping a shower after I clean the toilets or letting the bed go unmade.

But I love the water. It calls to me. To have a body of water lapping at the dock of my rental house is a temptation on par with Timothy Olyphant. Put a lake or Timothy Olyphant in my backyard and I’m diving in.

Well, I don’t dive into lakes. First, I’d never risk a spinal cord injury from bashing my head on the rocks of the shallow lake shore. And Naegleria fowleri gets to your brain when affected water forcefully gushes up your nose.

So no diving. Or jumping. Just gentle easing into the water while you scan its depths for alligators and snakes.

OK. Yes. And dorsal fins.

I decided to see how far I could swim in the lake. I tried not to think about alligators and Naegleria fowleri and snakes. I just swam.

I was reluctant to turn back when the time came. The water buffeting my body, the mountains hugging the lake, the clouds hanging in the brilliant sky – it was worth the risk to my brain. The cold air and colder water were bracing. Invigorating. Renewing. I could probably forget about the snakes, right?

As it turns out, yes, I could forget about the snakes. Something worse was waiting for me.

I’m about to get scuba certified. That’s a whole other horror we’ll discuss later. For now, just know the certification requires me to tread water for 10 minutes.

I was concerned this would be both physically challenging and colossally boring. Could I prevail in both battles? I had a whole lake waiting for me to find out.

I slipped my phone into a plastic bag, sealed it tight, and set the timer. Don’t worry – I did my alligator scan before I started the timer. I wasn’t going to cheat, but I wasn’t going to be reckless, either.

I pushed away from the dock and gently treaded water. I spun in a slow circle, taking in the mountains, the miles of cold water. I skimmed the surface for snakes, alligators, great whites.

Ugh. Let’s be honest. I looked for Nessie too. I am ridiculous.

Treading water for ten minutes in open water is psychological. Probably because I’ve seen Open Water. I was bored but very, very vigilant.

My timer shrilled from the dock. Elated, I turned toward the sound, shouting for my husband and son. I’d done it! Treaded water for 10 minutes! I didn’t let my wandering mind propel me to the dock. I had triumphed.

That was when I saw them on the dock. Staring at me.

Not my husband and son. Two – I don’t even know what. They were the size of my palm, with many legs and giant white abdomens. One stood on each side of the dock, sentinels to my challenge. They blocked my exit from the water.

My calls to my son and husband became more frantic. I yelled for them to keep my oldest – who has a deep fear of spiders – away from the dock.

“Why? What’s up?” my son asked as he ran onto the dock.

I yelled for him to stop. If those enormous pregnant lake spiders devoured him, it would be up to his father to rescue him. I was going nowhere near dock arachnids big enough to wear my dog’s harness.

I needn’t have worried. My son’s barrel dive onto the dock startled the gravid creatures from the black lagoon. They ran, plunging between the dock’s wooden slats, going beneath its wobbly surface.

Beneath. Where there’s nothing but rocks and water.

Could they swim? I wasn’t waiting to find out. I clambered onto the dock, shook out my towel in case their brethren waited for me in its warm folds, and hightailed it for the house.

Giant dock spiders. The one thing I hadn’t anticipated. No book, no documentary, no National Geographic article had prepared me for this. Their forms will linger in my brain when I scuba certify, like the afterimage burn of a camera flash.

That would make a great story – giant many-legged lake monsters stalking unsuspecting swimmers while lake swimming. Scuba divers surfacing in water teeming with white-bellied arachnids. Mutilated fish washing ashore.

Well. We know what I’ll be thinking about during that scuba certification.