Bozo, he felt it first and no they didn't all feel his presence until he started fighting Kaido and causing noise and destruction
They literally feel his presence on the same page as Sanji. Its literally the panel next to the one of Sanji sensing it.
You are literally just lying here.
Idgaf what you "think"
Being able to detect a random onject inside a body of water meters away is insane. This is just downplay for downplay's sake
Bro...do you know how long a meter is?
Emphasizing meters does not make it more impressive.
Also, wasn't this a feat he had difficulty with???
I'd argue Luffy's observation haki was shown to be superior in FMI when he detected Caribou attacking Shirahoshi from a different section of the palace and noticing it before the others.
Oh no...you mean the scene where he detected a woman in "trouble"?
Honestly, I'm not sure whether that should go in the pro or against Sanji here.
Hell, I'm not even fully convinced it was observation haki.
The reason I think thats not a good feat for Sanji is simple.
IT LED HIM RIGHT INTO A TRAP!
Observation haki is supposed to allow you to read peoples intents, but he didn't detect that they were fooling him at all.
Hell, he didn't even detect that the woman being "harassed" was surrounded by dozens of other people, including a Tobi Roppo.
This is why I almost think of this as an anti-feat for Sanji's observation haki.
It legit does not make Sanji or his observation haki look good at all.
So you want to explain why him intending to look for assassins have him the ability to detect one merely aiming at him from a distance and elevation?
Yes dumbass we know he was looking for one, the impressive part is being able to sense it merely aiming at him
Because thats like, the point of basic observation haki.
If you can't detect the intentions of someone about to attack you than whats even the point of having observation haki?
Also, I hate to say it, but the guy was pretty clearly out in the open.
Its a good example of Sanji actually using observation haki, but I don't think its anything special.

Keep coping
What a pathetic cope response. By number Sanji has more CoO than anyone on the crew bar Luffy, and most of the verse. For fucks sake Oda literally tells us it is Sanjis speciality.
I am being a good sport in not even mentioning his CoO feats with women because genuinely we can include those too if we aren't feeling dishonest
You have proven that Sanji has observation haki.
I don't think you've shown that its something he has a unique proficiency for.
Its something he uses somewhat consistently to decent results(and other times to completely disastrous ones).