"CRU": what is this? (Russian letters.)

Years ago I used to see labels, sometimes on cars, sometimes stuck to buildings, with what looked like “CRU” but on closer inspection turned out to be three Russian letters, ess, yah, and tseh. Pronounced together they would sound like “syats.” (Rhyming with “dots”)
Today I saw a young woman in a post office with the emblem on the back of her shirt. I approached and politely asked her what it meant. She hardly spoke English, and the closest I could make out what she said is that it has to do with boating equipment.
:confused: