Firstly, I would like to say that I have not worn a suit nor tux for over a year and probably less than 5 times in the past 5 years so my selection and point of view could be a bit skewed ๐๐
So off the top of my head I would go with these 6 groupings of 3 watches each.
1st group: AP
Formal would be a 15202ST. I know it's not a classic formal watch but if Bond can wear a SM with a tux I don't see why I cannot wear a RO with one ๐๐
Casual would be a 15407ST double balance
Beach, pool, sport's activity would be a ROO LE on rubber strap
2nd group: JLC
Formal would be a Duometre QL black dial. If it were a true black tie event, then maybe I would choose my MUT 34 but I think the Duometre QL could also work.
Casual would be a Duometre Chronograph
Beach, pool, or sport's activity would be an Extreme Lab 2.
3rd group: Richemont
Formal would be a Richard Lange Pour le Merite.
Casual would be a Zeitwerk.
Beach, pool, sport would be a JLC Navy Seals Alarm since I cannot seem to acquire an Odysseus or this could have been a Lange group ๐คทโโ๏ธ๐คฆโโ๏ธ
4th group: Swatch
Formal would be a Jaquet Droz Grande Second with black enamel dial
Casual would be a Breguet 5247BB white enamel dial
Beach, pool, sport's activity would be a Blancpain Fifty Fathoms Complete Calendar
5th group: Patek
Formal would be a Patek 5070G
Casual would be a 5990/1A
Beach, pool, sport's activity would be a 5164A
6th and final group: Independents
Formal would be a DeBethune DB25
Casual would be a FPJ CB
And to round everything out with a watch for the beach, pool, or sport's activity would be a Ressence diver