What They Have in Common
Both shoot to ±1 yard accuracy (at reasonable distances), both have slope with a legal tournament mode, and both run on a CR2 battery — which you can find at any pharmacy, mid-round emergency included. Six-power magnification is standard for this price tier. These aren't competing on the basics; they're genuinely solid in the same ways. The differences are in how they're designed to be used.
Where They Differ
Display and Optics
This is the whole ballgame. The Z30 uses a transparent OLED red display, which means yardage numbers float in your field of view rather than sitting in a separate LCD panel inside the eyepiece. It's a genuinely different viewing experience — cleaner and easier to read without hunting for the display. The COOLSHOT 20i GIII uses a standard internal display with Nikon's multilayer coating on the lenses, which is a real optics advantage. Nikon makes cameras for a reason; the glass quality here is noticeable. You're trading a slicker readout (Garmin) for a potentially sharper image through the lens (Nikon). Depends which one you care about more.
Size and How You Carry It
The Nikon weighs 4.6 oz. The Garmin weighs 7.4 oz — more than 60% heavier. The Nikon is also physically smaller in every dimension. If you're walking and carrying, that weight difference adds up across 18 holes. The Garmin has a cart magnet built in, which tells you something about who it's designed for. It wants to live on a cart rail, pointed toward the fairway, ready to grab. The Nikon wants to live in your pocket or a bag pouch. Neither approach is wrong, but they're clearly aimed at different setups.
Slope and Tournament Handling
Both have slope, and both have a way to turn it off for tournament play. The Z30 uses what Garmin calls a "tournament-mode light" — a visual indicator to confirm slope is off, which is a small but useful detail if you're the type who panics on the first tee wondering whether you remembered to toggle it. The COOLSHOT 20i GIII has a physical slope switch on the body. Honestly, both work. Probably the switch is slightly easier to confirm at a glance, but the indicator light on the Z30 covers the same ground. You'll toggle slope off for tournaments. You'll probably forget at least once either way.
Warranty and Range
Nikon backs the COOLSHOT 20i GIII with a five-year warranty. Garmin doesn't publish a matching figure in the spec data. That's a meaningful difference if you're thinking about a rangefinder lasting you the next few seasons. The Nikon also technically ranges to 800 yards, versus 400 to the flag for the Garmin — though 400 yards covers every flag you'll ever shoot at, so that one's not a practical edge.
Who Should Buy Which
Get the Garmin Approach Z30 if:
- You ride in a cart most rounds and want the rangefinder mounted and ready without fumbling for it
- You like a clean, floating OLED display and don't want to hunt for the yardage inside the eyepiece
- You want Garmin's ecosystem features — Range Relay, Find My Garmin — and use other Garmin devices that might talk to it
- You're the golfer who has their cart setup dialed in and treats the rangefinder as part of it, not something you pocket and unpack every hole
Get the Nikon COOLSHOT 20i GIII if:
- You walk most of your rounds and 130 grams vs 210 grams is a real quality-of-life difference over 18 holes
- You trust Nikon's optics reputation and want the sharper glass for confident target acquisition on longer approaches
- You want a five-year warranty on a $220 purchase — that's Nikon backing it hard, and it matters for the long haul
- You're the 12-handicap who plays three or four different courses a week, needs something compact that fits any bag setup, and just wants it to work
The Bottom Line
Nine dollars isn't the decision. Lifestyle is. The Z30 is a cart rangefinder with a genuinely cool display. The COOLSHOT 20i GIII is a walking rangefinder with better glass, a longer warranty, and a body that disappears in your pocket. Most club golfers who walk more than they ride are going to be happier with the Nikon — lighter, easier to carry, and Nikon's optics are the real thing. If you're a cart golfer who wants the magnet mount and the OLED readout, the Garmin earns it. But for the typical buyer at this price, the Nikon's combination of weight, warranty, and glass makes it the easier recommendation.
Get the Nikon COOLSHOT 20i GIII.
See Also