Whiskers are specialized hairs that are especially sensitive to touch. Your cat uses them to know when it’s walking along a wall in the dark. So why would a swimming seal need them? Oh, wouldn’t you like to know! Have a listen. I guarantee the seals will impress you.
The paper is:
Niesterok B., Y. Krüger, S. Wieskotten, G. Dehnhardt, and W. Hanke. 2015. Hydrodynamic detection and localization of artificial flatfish breathing currents by harbour seals (Phoca vitulina). Journal of Experimental Biology. DOI: 10.1242/jeb.148676.