This model's been out for a couple of years, but I've never seen a review of it. So for you who are considering getting one, read on.
I've had a number of G-Shocks but, unbelievably, never a 5600-style square. So I decided to pick one up, and in a wild color (red) while I was at it. Enter: the G-Lide. I picked it up at Zumiez while watching my nephew compare skateboard wheel bearings for 70.- USD.
The G-Lide 5600's are supposedly designed for ocean water-sports enthusiasts, particularly surfers, hence the model's signature feature: the Moon-Tide chart. (A surfer wants to know when the tides are high or low to know when the waves are ideal. The moon governs the height of the tides.) The model's slim, lightweight nature would be preferable to a larger Gulfman, I would imagine.
So, anyway, the review:
The standard outer box - hexagonal foam-lined tin - cloth baggie treatment. Nothing special, but those tins are actually pretty useful, I think.
This has the 3151 module. It's not atomic, nor is it solar, but the batteries in these last a long time and it's not like the non-atomic ones are innacurate.
Beyond that, it's got the usual stopwatches, world timers, countdown, alarm. Normal stuff.
The tide and moon stuff is the interesting part. To set it, you need to know your location's UTC-offset, longitude and lunitidal interval. There's ways to calculate it, and if you live near a major city Moon and Tide Graph Settings - G-Shock Wiki | casio watch resources will help.
After that, you can select any date in the future or the past and it will tell you the moon phase and the time of the high tide. Good for planning a trip to the seaside.
I opted for the red one, though black and white exist as well. The red is a bright, glossy Ferrari red. It has some micro-sparkles in the finish as well, which show up under bright sunlight. The resin straps have a little pinstriping detail, in a further nod to surf culture. The outer surface of the strap is glossy, the inner strap and keeper are matte.
It's typically G-Shock lightweight and comfortable.
I like the square G-Shocks a lot. I always have but never put down the coin for one. It's a very comfortable watch. Very easy to read and looks great to boot. A worthwhile buy for brightening up your look with a neat, if somewhat esoteric, function.