No, the boat’s on fire! No, the boat next door is dumping water! What is that noise?
Shortly after arriving is La Paz, we became aware of a noise, only heard when the boat is fairly quiet, a kind of crackling. At first, we thought it was raining, but with nary a cloud in the sky, that seemed unlikely. The noise was a kind of crackling or snap-crackle-pop sound. So, maybe splashing water from another boat, but we didn’t hear it outside as loud as it was inside. It sounded a bit like fire too. Or maybe water spraying through a hole in the boat belowdecks.
It sounded louder forward. We stuck our heads into the anchor locker in the bow, and it was louder still, but coming from below. We stuck our heads into the bilge (yuck), and it was also louder, but coming from forward.
When you’re on a boat, there’s no end to the imagined possibilities of an unidentified sound, most of them ultimately leading to the boat sinking. We finally gave up and went to sleep.
The next day, with a little help from our friends on C.A.T., plus a little googling, we figured it out: pistol shrimp!
Before I get into the details, I’ll warn you: when we told another boat about this, they were absolutely certain we were pulling their legs. But it’s true. Really it is. I couldn’t make this up.
Pistol shrimp (https://en.wikipedia.org/wiki/Alpheidae), an inch long snapping shrimp, have two claws. One is larger than the other, and can be cocked back and then released very, very quickly. When released, it creates a bubble, which then rapidly collapses, releasing a huge, but very local force (https://www.youtube.com/watch?v=XC6I8iPiHT8). The temperature in a very small area actually gets hotter than the sun. And makes a crack sound. It’s used to stun prey that the shrimp then eats.
What’s as amazing as the hotter-than-the-sun bit, is that to create the constant crackling sound that we hear, there must be hundreds or thousands of pistol shrimp near our boat doing this all the time.
Nature is so weird.
