There Are Two Genes Called SNORKEL1 And SNORKEL2
Deepwater rice carries two genes called SNORKEL1 and SNORKEL2. That is their real name in the literature. Nobody added it later as a joke.
They do what the name says. When floodwater rises and submerges the plant, ethylene gets trapped inside it. The trapped ethylene switches on these two genes, whose products trigger dramatic internode elongation through gibberellin. The stem shoots upward and the leaves stay in the air. The long hollow internodes act as snorkels for gas exchange.
The 2009 Nature paper that identified them showed the system is inherited rather than invented: wild Oryza rufipogon has both functional genes and responds the same way, while O. nivara has an inactive copy of the second and barely responds at all. A standard non-deepwater variety showed no ethylene-driven elongation whatsoever.
This is not a curiosity. It is being bred into rice for flood-prone lowlands, where the alternative to outgrowing the water is losing the crop.
One number we are not giving you: the widely-repeated figure for how fast deepwater rice grows per day. It is everywhere. We could not find it in the paper or in the university's own release, so it is not going in here. The genes really are called SNORKEL. That part needs no embellishment.