You cannot simply declare a ball lost Under the Rules of Golf, a ball is only officially lost if it has not been found within three minutes of a search beginning in the estimated area.
Only specific people start the search clock The three-minute countdown begins when you, your partner in a fourball, or your caddy starts searching — not your playing companions, spectators, or other players.
Deliberately delaying your search is not allowed If you are capable of walking to the search area but choose to hang back, the clock can still be deemed to have started from the moment you could and should have begun searching.