First full relaxation day in Seogwipo, and we are exhausted. We lumber out of bed at something like 0900 in no state to move anywhere. Miraculously, our muscles aren’t overly sore; it’s more of a pervasive general fatigue that reaches into every part of our bodies, making even the idea of physical activity anathema. So we lie about for a bit, reading and playing games and generally working up the strength to go get the food we know we need.

Finally we succeed in getting out the door (good thing we’re on the second floor, and not the fifth or something) and to breakfast. With some food in our stomachs, we can at last contemplate doing something, and we settle on Seogwipo Submarine as a suitably lazy form of entertainment. Besides, “ride in a submarine” is on Valkyrie’s bucket list, and when else are we going to have this kind of opportunity? It’s settled; we amble down (yes, actually walking somewhere!) to the port, fork over 55 000 KRW each (about 50 USD), and are soon on our submarine adventure!

There’s a quick ferry ride out to the submarine, punctuated by K-pop and all manner of incomprehensible announcements in Korean. We shrug and peer out the windows, watching the port grow smaller as we head out for the submarine dock. Jeju’s southern coast around Seogwipo has a series of tall barrier islands, presumably the eroded remains of offshore oreums; these are host to beautiful soft coral blooms, and the one we’re aiming for even has a shipwreck down at 40m! The Seogwipo Submarine experience is definitely touristy, but likely worth it if a) you can put that aside and b) you’ve never been in a submarine before.

Having completed our PADI Open Water Diver course earlier in this trip, it’s also cool to see what there is below 18m: less light, different types of fish… the light really does taper off quickly, although it’s not as dark as we expected it would be when the submarine bottoms out at 42m depth. The shipwreck is actually pretty recent, about 10 years old - a mackerel fishing boat that hit some bad weather and sank, though fortunately the crew all made it out alive. One of the staff is a proper polyglot; he chats us up in decent English before trying out his Chinese on the family next to us. (They give up on this, though, and ask him to speak English, which tarnishes the polyglot image somewhat. Still, credit for effort!)

Did I mention we’re still exhausted? After the submarine ride, we make it as far as the convenience store just up the road before hailing a taxi for the uphill slog back to the guesthouse. We feel absolutely no shame about this, having just completed eight half-marathons in ten days with 15kg packs in sauna-like weather. No wonder we’re dead tired!

The rest of the day is definitely uneventful: we grab lunch at the 15 bowls place again, though we get their bibimbap instead; we spend a while lolling about in a trendy cafe just opposite the museum; we get some more food while walking back through the market; we nap and read some more before stepping out for dinner, then nap and read even more. Exercise-induced fatigue is no joke: as top coaches and athletes know well, overtraining can leave you much weaker for as long as a week while you recover. We’re definitely feeling that sort of thing now.

Given our condition, we resolve to take an extra rest day here. Actually, taking a realistic look at our itinerary, we haven’t got time to complete the circuit of Jeju in this weather - not unless we want to collapse Pheidippides-style at the end! Maybe we’ll use the excellent bus system to get around to some of the more popular trails, then spend a bit of extra time taking the ferry/train combo back to Seoul. It’s always good to have flexible plans…