A pause, followed by several rapid heartbeats.

I love the water,
But I'm a terrible swimmer.
When I was 8, I was almost swept out to sea by a riptide;
Or at least that's what it felt like,
As a scratched and clawed at the sand,
And slid backwards towards the sea.

I'm not afraid of water,
It's heights that get me.
There's no anxiety,
It's just when I get up there and all of sudden,
Zip. Guts in a not.
And I'm almost less safe on the descent,
Than if the fear hadn't struck.

Now bikes, traffic,
And the dark?
I'm old hand.
There is no fear there.
All the accidents that I've almost been in,
There's no trepidation:
Just concentration, the proper and precise maneuver,
And then a pause.

Followed by several rapid heartbeats.