In the Mediterranean, there are special kinds of reefs covered in long, tough leaves called posidonia. From above, they look like waving pillows, or particularly coarse hair. From further away, they make wide, dark spots on the sea floor. Underwater, they look like prairies, with myriads of grazing fish.
Posidonia are the Amazon of the Mediterranea sea floor. Stumbling on a reef underwater feels like crashing a party. Coloured fish swim all around you, others burrow in the sand and dry leaves, waving their barbels and tails, others flee in schools when they see you approach. Starfish and anemones make bright spots on the bottom. Clams as wide as two hands gape at you, covered in hair-like seaweed. Every now and then an octopus hides from sight. If the sun is bright above you, its rays will make milky curtains in the water. It’s an exceptional sight, a few dozen metres away from the beach.
I can’t really explain why, however, but for a few years now, the thought of swimming over posidonia has filled me with dread. If I feel long leaves brushing my legs as I swim by, I feel close to panicking. Especially if they’re really close, which makes no sense because if the water is so shallow, there would be absolutely no risk of drowning, and stepping on posidonia is much like stepping on a bed of dry leaves in the forest. And yet, somehow, they’re frightening. Not just to me, either: I was a little relieved to discover that a lot of people I know share this fear. Why, I have no idea.
So I recently decided to fight the fear, put on a snorkel and diving mask, and go swimming above the reefs. And it was wonderful. I stopped there for a moment, trying not to disturb the fish, hearing nothing but my breath amplified by the mask, watching schools of fish swim all around me, paying no attention at all. The sun was high in the sky and the water crystal-clear. It was beautiful, peaceful beyond saying. And yet… I still felt ill at ease. I swam away and came back every now and then, so I wouldn’t stay for too long above the sea grass.
There is something about those reefs which cannot make one entirely comfortable. However warm the water, however long you spend getting acquainted with breams and giant clams, this is not your home. You’re not truly supposed to be there and you know it. You’re disturbing something, and you’re only safe as long as that something tolerates you. This is not your geography, not even your geometry. Spend too long swimming from reef to reef and you won’t know where you are. Well, you will know if you raise your head above the water, but once it’s down again, you’ve crossed the line back into that world that isn’t yours. There are no sounds aside from your breath, no feelings except from the water, and as for sight, you have to choose between the familiar surface, or the depths of the sea. It is beautiful, beyond compare. But it is not your home.