I would suggest raising the breather vents and then you wont have problems going deeper.. I have gone as deep as just below the hood hitch but kept it slow. Even that I did only after raising the vents. So look into that and you ahouldn't have too many problems other than corrosion..
2009 JK Unlimited Rubicon
3" BDS springs, Bilstein Shocks 3-5"; BFG M/T KM2 on Vtec Raptor matte black; Aberle Front stubby, Body Armor rear w/ tire carrier; P/P Skid plate system, Expedition One JK rubi skid plate, P/P Inner C's gussets, Purejeep Rocker/Slider; Reid Racing Knucles, Dynatrac Prosteer Ball Joints; Superchip Programmer; PIAA driving lights