The deck creaks softly beneath your feet and the ratlines slap lazily against the hydrogen-filled envelope above your head. Your nose is filled with the sharp tang of the cloud sea, as the beige and salmon clouds roll and roil beneath you. It's a beautiful day; the sun is bright and high overhead, the clouds in the sky are tiny and fluffy, and the shade of the envelope narrowly keeps you out of it. The great wheel is high in the sky at these latitudes, sharp and delicate, like silver lace strung across the sky from east to west.

Without warning, the deck is shaken by a roar that hits you more like a hammer than a sound. Off the starboard bow, less than a mile away horizontally and only a few fathoms down, the clouds split, revealing a broad, leathery back. As it rises, the clouds part further, as if the sea itself is giving birth. It rises further, and you soon realise that this beast is the size of a small ship, like a frigate or a destroyer. It moves its fins lazily, propelling its long, grey bulk through the air. It's nearly twenty fathoms long and five fathoms across, roughly cylindrical, with a conical nose and a wide, fluked tail. It drifts through the air, kept aloft by vast, internal bladders filled with the same gas as your envelope. It bellows again, expressing an emotion you can only guess at, and slowly tilts down towards the clouds, following a wide, lazy arc through the air below you and diving into the clouds once more.

When the leviathan breaches, it is considered a blessing to be present.