Very busy frequency. Likely legal marine users, but operating in-between ITU channels. 6519 kHz USB and 6522 kHz USB are both ITU standardized 6 MHz marine radiotelephone frequencies, 6520 kHz USB is in-between frequencies (but easy to remember).
Sounds like it could be Tagalog language. Good signals via the G8JNJ SDR receiver (Wessex SDR receiver) located in the South West UK. Lots of activity on the 3 MHz, 4 MHz, and 6 MHz marine bands this evening.