Notes

Reading a tide table backwards

A tide table tells you when the water will be highest and when it will be lowest. It does not tell you the thing you actually need, which is how fast the water is moving at the moment you are standing on the shingle deciding whether to get in.

The rule of twelfths fixes that with arithmetic you can do while shivering. Divide the range into twelfths, then spend them across the six hours between high and low: one, two, three, three, two, one. The middle two hours carry half the water. If you want the current at its weakest, you want the first hour or the last.

Nobody drowns in the arithmetic. They drown in the third hour, which looks exactly like the first hour from the beach.

Eleven degrees

Somewhere around eleven the cold stops being a sensation and becomes a schedule. Above it I get in and swim until I am bored. Below it the first ninety seconds are spent entirely on breathing, and whatever is left after that is the swim.

I stopped timing myself in minutes and started counting strokes, because minutes are a thing you check and strokes are a thing you do. The number that matters is not how long you stayed in. It is whether your hands still work well enough to dress yourself afterwards.

Three things that are not currents

Wind chop

Short, steep, and loud. It moves the surface and almost nothing else. It will exhaust you without carrying you anywhere.

Boat wash

Arrives late, in sets, long after the boat has gone. The only one of the three that will genuinely put water in your mouth mid-breath.

Apparent drift

You fix your eyes on a post on a moving shoreline and conclude you are being swept out. Two fixed points on land, one behind the other, settle it in about four seconds.

On not swimming

Half the entries in the paper version of this notebook are about days I looked at the water and went home. That is not a failure of nerve, it is the whole skill. The sea is there every day. You are not.