This is a single inlet version:

upgradeparts-rcboat-waternozzle-for cooling-single

This one has a much longer nozzle:

upgradeparts-rcboat-waternozzle-for cooling-single-vlong

This is a dual inlets version:

upgradeparts-rcboat-waternozzle-for cooling-double

This one has longer nozzles. There is also an extra inlet in the middle for producing water steam at the tail.

upgradeparts-rcboat-waternozzle-for cooling-double-vlong