A lot of new construction decks around here are done with TWP type of stain. It has the viscosity of water so it can be applied with a pump type garden sprayer.
TWP 100 is oil based but it is a translucent toner and has a more natural look than heavy semi-transparent stains....
If you use an airless, a complete clean up ( pump/gun & line ) before spraying latex can be a beast, if you have a lot of them to do dedicate a spray rig for those jobs.
PS
Before applying any stain to a new treated deck the deck board's surface needs to be "opened" by power washing or sanding.