The HydroConquest is Longines' dive watch line, between the Conquest and the pricier Spirit. This 2026 version has the L888 calibre ETA-based, but Longines have squeezed 72 hours of power reserve out of it. For context, plenty of watches at twice the price give you less.

What are the specs?

  • 39mm stainless steel case, 11.7mm thick
  • Blue ceramic bezel and blue dial
  • L888 automatic movement, 72-hour power reserve
  • 300m water resistance
  • Stainless steel bracelet with double security folding clasp
  • 5-year warranty, Swiss made

This is the 39mm version the one to go for if 41mm sits too big on your wrist. Ships in 4-6 weeks from Watches of Mayfair in London.