[CW] Ghost on 40 meters....???

[dory]

QRG  7020 KHZ
Time: 2245 gmt

This evening while tuning around on 40 M as above I
heard the following

transmission with an extremely  strong signal...

VVV VVV VVV de NPN NPN NPN

They then sent ZWC ZWC ZWC  as well as NERK ?????

Heard the above several times then went QRT....

I looked up the old Z code and ZWC means wipers
???or clicks here.

I thought the US Coast Guard was QRT on CW????

Anyone else hear this or have any explanations???

73

VE1DS