White something on PSS Shaft Seal coupling

[dmksails]

My boat has spent the last 3 months closed up at the dock. I've returned and in getting everything in order, I noticed this white stuff coating the front ring of the seal.

This is freaking me out. Any suggestions as to what this is and how serious an issue it is?

[Sailmonkey]

Looks like salt. Ours does that too, spray the water hose on it and watch it dissolve.