After an operative submerged condition a submarine needs to take air from above the water surface. This implies that the intake mast has to be designed avoiding the water flow down the mast when operating in snorkel condition. The present paper is dedicated to an experimental and numerical investigation of  the flow field around a snorkel mast. The main objective is the determination of the pattern and extension of the spray around the deplumer.  Numerical simulations performed with a Smoothed Particle Hydrodynamics solver are computed as a complement of the experimental tests achieved in the INSEAN Towing Tank n° 1 facility. The numerical solution of such kind of flow are very challenging because of the high deformation of the free surface and the necessity to simulate correctly the water jets generated for high forward speed condition.  To overcome the limit of the standard SPH solver an innovative and promising  SPH model has been adopted for such a problem.  

In order to more accurately predict the flow around the deplumer, the wave pattern generated by the submarine itself should be taken into account. Indeed, in the region close to the snorkel, the local wave pattern may modify the flow during the interaction with the Snorkel mast. In a first approach, a simplified problem is defined considering the snorkel mast cruising in forward velocity and neglecting the effect of  the submarine as well as the effect of other infrastructure (e.g. periscope, antennas) positioned upstream. This approximation should allow understanding the capability of the deplumer profile to avoid entries of water in the air-intake system. Further, in such a simplified condition it is possible to perform an experiment in scale 1:1 reproducing the flow at the correct Weber number (i.e. wrong scale effects related to the water surface tension are avoided).