Spanish for "fishermen". They're the two-way stations (generally marine mobile, I'm sure some of them are land-based, or at least marina-based...) chattering away on various frequencies on 43 meters (and in various other parts of HF, cf. 25-30 MHz when the band is open...). They usually use LSB mode and 6925 kHz is one of their favorite frequencies. You'll usually see them using 5 kHz steps but sometimes they'll pop up on a "split" frequency, for example 6919 kHz or 6868 kHz.
You'll hear Spanish, Portuguese and sometimes other languages (including English).
They'll sometimes even play music to each other, and when they do, you'll see a thread on here for "Peskie Party Radio"