IMHO, the answer is "it depends..."
- If you are small / petite hiking sandals or low shoes may work for you.
- If you are very nimble and light on foot and walk lightly on the earth, the same applies...
- If you are larger, but have strong ankles, the same applies.
- If you are of any size, but are carrying a rucksack lighter than 10 Kg all-in weight, same as above.
However,
If you are:
- large-framed (like me),
- heavy for your height (like me),
- have notoriously weak ankles (guilty), or
- typically carry upwards of 11 - 12 kg. in your rucksack (you guessed it, tag, I'm it),
I seriously recommend the extra support provided by study, well made, ankle-high or mid-height boots. Personally, I swear by my Keen Targhee II mid-high waterproof (Gore-Tex) boots. But, and I hasten to add, there are MANY quality brands of footwear out there.
Also, I plead with you to have the shoes fitted, while you are wearing the socks you plan to wear on Camino, and at the end of a day where you have been on your feet a lot, by someone in a shop that actually knows what they are doing. This means buying your boots in an outdoor sports shop that has staff who are accomplished hikers or runners. They understand the principles I relate here.
If you MUST economize and try to shop online, I still recommend being fitted in a shop, then using that knowledge to shop for the best price for the identical item online. However, in my experience, once you factor shipping costs, the end result is usually near the same. I suggest that the amount saved, if any, is false economy. So, I usually advise keeping your trade / business local. If you have difficulties with the new shows, this will be beyond value.
Regardless of the style of footwear you opt for, the boot, shoe, sandal should be sufficiently larger than your street shoe size to:
- Allow for wearing two-pairs of socks (ultra thin liner for friction reduction and wicking moisture from your feet, and a thick outer sock for cushioning and warmth)...
- ... and with the two pair of socks to provide a minimum of one-half size for daily foot swelling
- ... with the two considerations above, to allow for "splaying" or foot size increase from walking with a constant load for weeks on end, and
- ... must avoid your toes rubbing or banging against the inside of the toe box / cap, or overhanging the front of your sandals. You must have a "bumper" to protect your toes.
As regards my point concerning "splaying" after four Caminos, one each year, my feet are now permanently one-half size larger than they were before I started this benign madness called the Camino. I verified this recently using one of those funny metal foot measuring devices in a local shoe shop. My foot did not get wider, just a tad longer...go figure...
Also, and regardless of size, or style you opt for, the footwear should have an enclosed toe box or cap to provide maximum support for your toes on downhill segments. You WILL be sorry if your footwear is too small or does not afford this basic protection to your "tootsies."
When you are fitting your footwear, and with the shoes, or boots laced properly, intentionally kick something solid to see if your toes contact the inside of the toe box / cap. If the shop has a simulated hill (REI shops in the US usually do) walk up and down.
If laced properly, your heel should remain in the heel counter / box, and your toes should NEVER touch the inside of the toe box or cap. You should be able to wiggle your toes in the toe box. If your toes do strike the inside of the toe box, even if wearing two pair of socks, increase the size by one-half, or until the rubbing against the inside front of the toe box stops.
Remember, on the Camino, every up has a down. And coming down can be more perilous and dangerous to your feet than going up.
Over the years, I have seen dozens of folks wearing either too small shoes / boots, or footwear without a covered toe box, with blisters, bruises and lost toenails...not too mention lots of blood...yuck! It diminishes the quality and enjoyment of your Camino, can cause serious health issues. Moreover, it is so easily avoided by upsizing one-half or one full size, or more, as indicated here.
Remember, the two most critical items you will buy for your Camino are footwear and a rucksack. DO NOT SCRIMP. Buy what works best, regardless of the costs involved. In my long experience, you will remember the quality long after you forgot how much you paid for them.
I hope this helps.