So I've been meaning to do one of these for a long time and finally got it done. Very simple to build. I didn't take photos will building it but I will list my parts list, some photos, a video, and a a wiring diagram.
Yes I know I still need to paint the can and the cord. I would have used a brown cord but I had the white on hand so it was cheaper.
Parts used:
Used duck decoy
Used 500gph bilge pump
Automotive signal flasher
12v 7ah battery
Paint can
Used extension cord
Female terminal clips
2 pole waterproof screw on connector
Tools used:
Soldering iron
Wire Strippers/crimpers
Heat shrink
Heat gun
Sawzall
Hot glue gun
This connector can be found on eBay