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Do You Really Need a GPS Watch for Hiking? | 5 Features, Tested on Mount Amagi

2026.07.31

"With a smartphone, you can manage most things in the mountains." Honestly, that was my position for a long time.

One phone with a map app gives you your position, your route, your elevation. I never quite understood why anyone would add a watch on top of that.

What changed my mind was a full day on Mount Amagi, on Japan's Izu Peninsula. It isn't that you can't hike without a watch. It's that there were clear moments when having one changed how I walked. Here is what those moments were — including the parts where the watch didn't matter at all.

The Suunto Vertical 2 used here was provided by Suunto. Everything below is what I actually noticed over a day on the mountain, and I've left in the things I found underwhelming as well as the things that worked.

A phone is enough — but mountains add friction

Let me be clear about the starting point: for a day hike, a map app on your phone is genuinely sufficient. I don't want to be vague about that.

But spend a whole day out and small frictions start to stack up.

• Every position check means digging the phone out of your pack
• Rain gets on the screen, and a wet screen stops responding to touch
• On cold days your fingers are too numb to register at all
• Between photos and video, the battery drains steadily

Each one is trivial on its own. Across five or six hours of walking, they aren't.

Adding a watch to reduce that friction changed the day more than I expected. That was the real finding.

Why Mount Amagi is a good place to test this

Mount Amagi sits on the Izu Peninsula in Shizuoka. We started from the car park at Amagi Kogen, went through the Yotsutsuji junction to Banjiro-dake (1,299 m), then along the Uma-no-se ridge and past Hanadate to the highest point, Banzaburo-dake (1,405 m) — one of Japan's 100 Famous Mountains.

I chose it deliberately. Amagi is known for fog. "Crossing Amagi" is a phrase that carries weight in Japanese literature and song, and the fog is the reason why.

It is also densely wooded, to the point where you barely see sky. That keeps it cool, but it also means hours of walking through dim forest where light never quite reaches. For testing whether a watch screen is actually readable, I couldn't have asked for better conditions.

It had rained in Tokyo that morning, and the forecast was cloud. I genuinely hesitated about going. But the trails were quiet, the wet forest was beautiful, and I came away glad we'd made the trip. The rhododendron season had finished, though fallen blooms were still scattered along the path.

Not having to stop at junctions

The trail split early on in a way that wasn't obvious. I checked my wrist and took the turn — "I thought it was that way, but no, this way." Useful within the first twenty minutes.

Still, honesty first: Amagi is well maintained and well signposted. Where there are signs, you don't need a watch.

So what actually differs? The manner of checking.

With a phone: stop, take off the pack, open the app, wait for the map to load. With a watch: glance down while still walking and carry on.

Not breaking stride turned out to matter far more than I'd assumed. On routes with many junctions, and for anyone who hikes often, that difference compounds.

The sign at Yotsutsuji gave 1.6 km and 55 minutes to Banjiro-dake. Having distance and time on your wrist makes pacing easier to think about.

Being able to read the screen in fog

As expected, fog rolled in not long after we started climbing.

In dim forest, and especially against backlight, a phone screen becomes hard to read. Turning up the brightness often just makes the reflection worse.

The Vertical 2 has a 1.5-inch AMOLED display, and it stayed clearly legible in low light. The colours are vivid and it catches your eye outdoors.

Written down, "the screen is nice" sounds like a minor point. On a mountain it isn't.

When fog closes in, people get uneasy. Where am I, is this still the right path — that unease accumulates. Being able to see clearly on your wrist is what lets you think: it's fine.

It converts "I can't see" anxiety into "I can see" reassurance. That's where the value of a good screen actually sits.

Suunto, incidentally, is a Finnish brand that has been making outdoor instruments for ninety years. I rather like the object itself — it looks like a tool, and I'm happy wearing it day to day.

Your position, with no signal at all

Mountains have far less mobile coverage than people expect. Once we were into the trees, my phone dropped to no service.

The watch still showed a map with my position on it. Load the maps in advance and your location works regardless of connectivity.

Experiencing that is reassuring in a way that reading about it isn't. Not having to rely on a signal in the mountains matters more than I would have guessed.

From Banjiro-dake to Banzaburo-dake

Enough about features — here's the day itself.

At the top of a steep climb, Banjiro-dake (1,299 m) gave us an unexpected view of Mt. Fuji. With cloud forecast, I hadn't counted on it, which made it better. On the other side we could see the sea, out across Suruga Bay.

We stopped for lunch there. I'd brought yakisoba-pan — fried noodles in a bread roll, a convenience-store staple in Japan. At 1,200 m the bag had puffed up tight with the change in air pressure. Small things like that are part of why I like being up there.

From Banjiro-dake to the high point is 2.1 km, about 70 minutes. We left at 11:53, so we were due in a little after 13:00. Knowing "how much further, how much longer" on your wrist quietly helps. With the altimeter showing the climb remaining, you can pace yourself through the hard sections — another hundred metres or so of ascent, and that's it.

On the stretch that drops before climbing again, Mount Omuro came into view on the right: a neat rounded cone, one of Shizuoka's landmarks, with a chairlift to the top and a path around the crater rim.

Past Hanadate it was 0.9 km and roughly 35 minutes to the summit. This last section has ladders and chain sections. The steep descents were frankly frightening — mostly because there's nothing you can do for yourself if something goes wrong. The greenery through it was lovely all the same.

Then the summit: Banzaburo-dake, 1,405 m. There is no view. Just a quiet clearing enclosed by trees, which is very much in character for this mountain.

The descent takes about two hours. We started down at 14:30, due back at the Amagi Kogen car park around 16:30. Simply having that timeline in mind makes the walk down easier to sit with.

What mattered most: noticing a mistake early

This is the part I most wanted to convey.

Trails branch naturally. Boot prints spread out and it stops being obvious which line is the real one. Even reading the map properly, there's a moment — I think everyone has it — where you drift a little and think: wait, was that right?

So we deliberately walked off-route to test it. I left the correct path on purpose, slightly nervous, to see how far I'd get before anything happened.

The alert came much sooner than I expected. It genuinely surprised me. Go wrong, and you'd know about it well before you'd gone far.

You can't walk a mountain staring at your phone. A watch catches that drift early. That is the single reason I came around to thinking a GPS watch is worth having.

Route-finding errors are consistently among the leading causes of mountain incidents. Not a device that stops you making a mistake, but one that gets you back quickly when you do. Framed that way, it matters quite a lot.

The limits, honestly

Having said all that: a GPS watch is not a safety net you can lean on.

It's an electronic device. Batteries die, hardware fails, and GPS accuracy shifts with terrain and tree cover. Thinking "I've got the watch, I'll be fine" is the dangerous position.

Carry a paper map, a compass, and your phone. Then add the watch. Don't reorder that.

For what it's worth, wearing this hasn't reduced how often I read the map — if anything I check more, comparing what the watch says against what the map shows. More instruments means more to reason with, which is closer to how it actually feels.

The five features that earned their place

After a full day out, ranked by what actually helped.

5. Altimeter Knowing how much climbing is left, on your wrist. Pacing becomes much easier. Unglamorous, but it earns its place on a hard ascent.

4. Screen visibility (AMOLED) Fog, backlight, dim forest — precisely the conditions where a phone struggles. It turned "I can't see" into "I can see."

3. Position and heading Glancing down mid-stride at a junction instead of stopping to dig out a phone. The more often you hike, the more this adds up.

2. Offline topographic maps No signal, and still a map with you on it. Not depending on coverage was worth more than I'd assumed.

1. Being warned when you leave the route The clear winner. Not a device for avoiding mistakes, but one that lets you notice early and get back. No other feature came close.

In short: bring the phone, then add the wrist

The conclusion is simple.

Always carry your phone. Adding a GPS watch on top makes hiking safer and more comfortable.

I'd argue this matters most for people newer to hiking. Take away some of the worry about getting lost and you free up the attention to actually enjoy the walking.

It suits you if:

• You're starting to walk routes with a lot of junctions
• You've had a day where rain or cold made your phone unusable
• Anxiety about route-finding is getting in the way of the day
• You shoot photos or video and want to spare the phone battery

If you only walk short, well-maintained low mountains, I don't think you need to rush. A phone and a paper map cover it.

Amagi left me properly tired — it had been a while since I'd walked that far — and it was a thoroughly good day. The stillness of fog-wrapped forest isn't something you get on a clear one.

I'm also planning a follow-up on this watch after three months of use, testing battery life and GPS accuracy properly. This piece deliberately covers only what helps on a single day out, so if the longer-term picture interests you, the channel is the place to find it.

One last thing, if you'd like to weigh in: of the three — current position, offline maps, or the off-route warning — which would you actually want? There's a comment thread on the video.

*This article is based on a video produced with product support from Suunto. Specifications and on-screen behaviour can change with software updates, and GPS accuracy and battery life vary with conditions. Always carry a paper map and compass in the mountains.*

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This post contains affiliate links. Prices and specifications are as of the video's publication date. Most items are sold in Japan.

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