I disagree, that does not seem to fit Adams's style of humour and wordplay in the books. grandparent is just overthinking it; the image is of a ship that glides

I disagree, that does not seem to fit Adams's style of humour and wordplay in the books. grandparent is just overthinking it; the image is of a ship that glides through space like a fish gliding through water, but turns clumsy and lumbering when you actually try to steer it.