A thunderstorm over a rainforest is quite a sight to see. The clouds are huge, heavy and dark and they hang low over the trees and hills, dropping their contents straight downwards like a dumptruck tipping up at the top of a cliff and sending its load over the side to the valley below. The thunder is low and long and angry and rumbles across the Isthmus above our heads. The lightning hides above the clouds, lighting up the dark sky like a fluorescent bulb that’s on the blink – giving a few shuddering starts of light before stopping, as if exhausted, for a rest.

The clouds seem to be damaged by the thunder and lightning. There are strange vertical shreds of cloud that peel off and waft across the treetops, like a straggler wildebeest separated from the herd or a toddler who has lost its mum’s hand struggling to keep up on its own. I’ve never seen anything like them. They seem to get their feet caught in the trees and break up as they fall. I assume they are pure moisture, disintegrating into individual raindrops as they go, but it does look quite sad. It looks like a slow-motion trip and fall like you see in a movie, when you know the character has been shot and will be dead before they hit the ground, only instead of landing in a puddle on a dark bullet-filled night, they disintegrate into nothing at all, moisture meeting moisture as the rainforest drinks.

On the plus side, from the human point of view at least, all this movement causes a breeze, for which we are quite pathetically grateful. Because if I thought it was humid before, that’s nothing to what it’s like just before it rains! The clagginess of the heat and the wet combined sticks to you like a thin layer of glue, and I have no doubt I will have to change every single item of clothing, down to and including my underwear, before going to dinner.

The wind is now strong enough to start knocking down unattended and badly propped-up sunloungers, with that rather over-spectacular clatter you can only get from a plastic sunlounger, and the deck is virtually deserted. Even here, under the sheltery bit, I’m getting quite damp indeed. The rain is really coming down now, as if to prove the point. ‘This is a rainforest, doncha know?’ Big blattery drops smashing down onto the swimming pool and the deck, each bouncing over an inch back upwards, such is their eagerness to smash into the ground. When it’s coming down hard enough to show up on a photo, that’s pretty hard. It’s all very pretty.

The huge (and I mean massive – it makes us look small) container ship behind us and the hills behind them have pretty much disappeared from view into the white mist that has descended, and only the silhouettes of the closer trees remain to remind us that we are still in the middle of the forest, just easing our way out of the last lock at Millaflores, before beginning the run down to Panama City and the Pacific Ocean. We’ve never been through the canal during the rainy season before, and I have to say I’m rather glad we did. It’s quite a sight. I hope, however, when I say “run” down to the ocean, I mean “run”, because we need to get ahead of this storm! There’s a speed limit in the locks, but once we’re free, I’m rather hoping we’re going to really peg it out of here! I imagine the rain will stay in the rainforest, so once we’re clear of that, we should hopefully be clear of its weather too.

The mules are made of metal. I wonder what the rain sounds like on the roof of those?!

And low and behold, as soon as we clear the edge of the rainforest…