I found myself a watch with a depth gauge—two different ones, in fact. But choosing is impossible because each has its own advantages and disadvantages.
Here’s the Timex Helix.
Timex Helix
Pros: $45 price, has a thermometer, will almost certainly suit my purposes, large digits and good backlighting, memory of the depth and temperature of the last dive
Cons: stupid-looking, used, measures depth once every 5 seconds or manually, but pressing it manually is not recommended???,
measurements only in feet, accuracy of 30 cm.
Casio Marine Gear
Pros: depth in meters or feet, accuracy of 10 cm, decent appearance, metal case, new, has a barometer and altimeter, measures depth once every 3 seconds or manually (as many times as you want), memory of the last dive (seems to have it)
Cons: $64 price, no reviews or information online, no thermometer