If for whatever reason you don't want a Rolex then take a look at the Blancpain Fifty Fathoms Bathyscaphe. It's water resistant to the usual 300m, is a more comfortable 43mm wide (and 13.40mm deep) and even includes a transparent case back, which is a feature less often found on dive watches; though, this may be due to the increased thickness they give a watches case, the perceived weakness that they give and the additional cost involved.
The dive watch is a type of watch that really encapsulates what it is to be a luxury watch. It's simultaneously a functional piece of specialist equipment, needing to survive the punishing environment of being dragged down deep underwater, while still telling the time: but, they are typically built to extravagant specifications, being water resistant to 10 or even 100 times deeper than people will actually dive down to in reality. Few people will ever test these dive watches to their full capabilities!
The Rolex Yachtmaster II is a very peculiar watch in that it's just so spectacularly different to every other watch in the 'Oyster Perpetual' family that Rolex makes! It's like some rebellious sea-faring child of the Titan 44mm Deepsea  and the more sophisticated 40mm Yacht-Master.
This mountainous 47mm wide Oris is truly gigantic in size at a whopping 47mm wide and has a substantial 17.7mm case depth. It is not only Oris's first watch of its kind; but, 'the world's first automatic watch with a mechanical altimeter'.
Initially when opening the box for the Omega X-33 Skywalker Solar Impulse (ref. 322.214.171.124.03.001). I was a little apprehensive: this, is a quartz movement watch, from a company that increasingly wants to be seen as a truly luxury brand, by making more mechanical watches. The bright green and blue colours are strong and catch the eye, but lacks a little sophistication in my option. But overtime it’s a design that has grown on me. The casing is built from dark looking grade 2 titanium with an excellent matte brush finish, which maintains its crispness around stylistic detailing, and reminds the wearer of its status as a tool watch. It is a comfortable 45mm wide with two buttons on either side of the face keeping multiple lines of strong symmetry.
This is the new Moonwatch for the space race lovers who may not be able to afford an original pre-moon 105.012 or post-moon 145.012 Omega Speedmaster, being tested and certified by NASA to endure extremes in temperature, humidity, shock, pressure and vibrations. But unfortunately for some, these rare gems of timepieces also command a high asking price on the second-hand market. Costing 3 or 4 times that of the Speedmaster Professional Moonwatch I'm currently reviewing here (released in 2014). Or this watch could be suited to those who don't want the hassle of buying a second-hand original. What with finding one in a good condition, with a service history, from a reputable seller, at a good price.