The participants are probably from the same family as would be the boat.
As can be seen this large fishing junk has been dragged far out of the water well above any tidal rise. It will have been pulled out using a drum and cable or rope winch anchored to the shore with the Junk’s keel guided onto a greased log or planks to slide it up out of the water. Wooden props would be positioned to keep it upright.
In the days before powered winches, hull cleaning would be done by laying the Junk over on a beach in a receding tide and cleaning a portion of the hull between tides.
Date picture taken
1970