Sotheby’s latest watch events went rather swimmingly.

The auction house’s earnings in Geneva yesterday closed at $27 million. Helping Sotheby’s achieve such an eye-watering figure was Mercedes Gleitze’s ‘Companion Oyster,’ an ultra-rare Rolex prototype worn by the first British women to swim the English Channel on one of her many journeys across the water. And plenty of Breguet timepieces, part of Sotheby’s blockbuster sale from the watchmaker (the largest in decades), hammered down for quite the pretty penny, too.

Gleitze’s Rollie ended up fetching a whopping $1.73 million, heading home with an Asian private collector after they battling with three other bidders for the prize. And there was a good reason for all the hubbub. This 27 mm, 9-karat-gold Oyster helped Rolex garner recognition for producing tool watches. It had taken the watchmaker over 10 years to create a waterproof, shockproof, and dustproof wristwatch; it was the Oyster that first showed off Rolex’s patents for a fully sealed, waterproof case and a screw-down crown system. Gleitze’s iteration was likely a 1926 model, one that was made before the patent for the winding crown was obtained in 1927, making it extremely rare.

The famed swimmer wore the timepiece tied around her neck with a ribbon on October 21, 1927, as she attempted to cross the English Channel once again. (She successfully crossed the waterway on October 7 of that year and attempted to do so again after a rival claim questioned the legitimacy of her achievement.) And though that crossing wasn’t a success, her Oyster, with its gilt pink dial and octagonal case, still cemented its place in history.

The watches on offer at Sotheby’s A Celebration of Breguet’s 250th Anniversary sale, too, have also left their mark in the history of watchmaking. As you may have guessed, the event was centered around the legacy of Abraham-Louis Breguet and his house’s semiquincentennial, and there was plenty of merriment to go around. A four-minute tourbillon from the brand hammered down for $2,334,960, blowing past its top estimate of $863,027. No. 1890 offers up both the régulateur à tourbillon and the rare, intricately constructed échappement naturel, making it a host to groundbreaking innovation and technically advanced creations. Also surpassing its top estimate was a weight-driven pendule à trois roues skeleton timepiece that was personally made and used by George Daniels; the piece fetched a a cool $2,334,960, with an top estimate of just CHF 400,000.

Not to be left out is a perpétuelle montre à tact in 20-karat gold with ties to King George IV of Great Britain. The offering, realizing around $945,000, also houses many perfected elements from Breguet, including automatic winding, a calendar display, and a tact mechanism that can tell time silently or in darkness. Elsewhere in the sale, a Cartier Baignoire sold for four times its estimate, at $283,921, in a world record for a regular-size version of the model. Consider it proof that the secondary market is alive and well despite the turbulent times.