There’s a recent discussion here: https://cycle.travel/forum/thread/6835

There are many opinions, all of them correct, because it really comes down to preference (and budget). The right answer for you will depend on what kind of riding you do, what equipment you already have (or can get), and what kind of interface you expect.

We use a Garmin for 2 reasons.  1 it is fine for riding in the rain and 2 the battery life seems to be better 

A friend has just completed the LeJog solely using his smart phone for routing following Cycle.Travel routes. I'd like to get opinions for this approach from other Cycle.travel aficionados. Anyone? 

The two biggest battery hogs on a smartphone are (1) display (especially on bright days) and (2) cellular radio (especially in areas with weak / no coverage).

1. The "dim between turns" setting, or just locking your phone and relying on voice prompts, helps a lot.
2. Downloading the offline maps and using airplane mode will make a big difference. 

I do #1 but not #2. On an iPhone 16 Pro I need to plug in to my power bank after about 4-5 hours of riding, but I am usually fiddling with the map, taking lots of photos, listening to podcasts, etc. 

On modern iPhones you don't really need to worry about rain (IMO), but if the charging port gets wet the iPhone might refuse to charge. (Workaround: newer iPhones can charge reasonably quickly with a MagSafe charging puck. I always bring one.)

If all of that sounds more stressful than an additional device to buy, learn, charge, and sync, a GPS might be right for you 😉 

I was hoping to get a opinions of the ease of use and of the readability of routes on smart phones screens versus GPS devices. I understand the issues with batteries. 

A friend has just completed the LeJog solely using his smart phone for routing following Cycle.Travel routes.

Ken, based on what you've written it's quite possible that that person used a different app to navigate CT created routes. 

I was hoping to get a opinions of the ease of use and of the readability of routes on smart phones screens versus GPS devices.

Both of these criteria depend on the individual. Me telling you that Unit X or App Y is easy to use is of little use to you. Similarly with visibility. Your eyes are not mine.

As I understand it, you already have a phone and a Wahoo unit. The best thing you can do is to test both of them out in the way that you envisage using them. 

There is little more frustrating than finding ourselves in unfamiliar territory and then realising that we do not understand how our navigation works. Practice makes perfect. 

As I said before on a (now deleted) thread of yours, you will get a broader input to your queries on the mainstream cycling fora. Bike Forums (USA) have a dedicated Touring section as does Cycling UK & CycleChat (UK). 

Just to round this off and if the site owner doesn't mind (I recognise this is a 'help' forum), this may be the end of this discussion. I asked Samsung the question and this is what I got.

• General improvements: Samsung constantly seeks to improve battery life across its devices through hardware and software optimization. These improvements would inherently benefit GPS usage, including routing for cycling trips.
• Challenges of continuous GPS: GPS is known to be power-hungry. Achieving truly "day-long" battery life with constant GPS usage on any smartphone is challenging without external power sources.
• Workarounds: Users often rely on power banks to extend battery life during long GPS usage.
• Alternative devices: For dedicated cycling performance tracking and long GPS usage, devices like Garmin bike computers are often preferred.
• Samsung's focus on fitness features: Samsung is incorporating cycling-related features in its devices, such as the Cycling FTP (functional threshold power) test on the Galaxy Watch. This suggests an interest in supporting cyclists, which could lead to further battery optimizations for GPS use in the future.

Just for info, and thanks for the replies, I have trialled an old phone (Iphone 7) and this works excellently in aeroplane mode with downloaded/imported routes.

No need to buy a satnav if you have a spare phone kicking about!

Mark, When I have tried that in the past (I do have spare phones that died at one time and then were resusitated) my provider tells me I already have a phone and cannot have another. How do you get around that?