where ?

Have you tried meditating there? Sometimes then people will show up.

yes 24 hours meditation i tried

ok. got the same situation.
I visited this bridge before visiting kaer trolde and Yennefer and i didn't find a guy.
But after visiting Yennefer I returned and find a man on the beatch where Gerald should swim. (correct location you can see at this video https://youtu.be/IMdFfTCMhAI?t=8m10s (with timestamp) )

If I recall correctly its the quest where you need to talk to the pearl guy right? If so he's underwater. There should be an entrance somewhere around that area, its an underwater cave.

the marker is still by the bridge but nidas is now down by the beach..more amatuer coding by CDPR...dont expect these fresh out of college kids to ever get this game running balanced and decently...combat system terrible...buggy quests, buggy achievements, loot system terrible, crafting system terrible....they know how to add their story tellers stories to an unreal gaming engine and then bug the crap out of and TRY to fix it over months while messing other things up lol....I guess the real talent has left the building.....im so pissed at the lack of effort that went into all aspects of this game. Anyways, ya he's now down by the beach...I too had to once again break my immerision to get online and figure out why he wasnt in the yellow circle. Stupid programmers dont even know how to move a yellow circle.

thnx guys