We walked the spiritual variant at end of May 2019. It was an interesting walk, with a lot to see; including the spectacular arrival at the ria de Arousa, walking along its edge as you arrive into Vilanova de Arousa (which is where you can get the boat ride from). The descent from Armenteira follows a river course through forest paths and many old stone watermills - hence its name: Ruta de Pedra y Auga. It is a beautiful path and brings you eventually to Ribadumia - where you can find accommodation, or push on to Vilanova de Arousa.
The alternative route starts just a few km outside Pontevedra you first head toward Poío, where there is an old monestary of interest.
From there you wind your way along paths and roads to eventually arrive at the waterside and make your way to the charming old fishing village of Combarro - famous for its many small "Hórrios" (old grain storage sheds made from stone or wood) at the waterfront - and it's small streets that meander through the beautiful little village. Here there are many options to eat typical Galician seafood dishes - as well as many tourist shops.
There is quite a steep hill, which starts its ascent as you leave Combarro (which is approx 10km from Pontevedra) then dropping down from the summit you soon arrive at Armenteira - which has a wonderful old monastery. There is an albergue there too, and places to eat. So it's a place to stop the night, providing there are beds available of course.
The alternative route is much longer than the central route from Pontevedra to Caldas de Reis, so skipping 32km of road walking by taking a 23km boat ride doesn't actually reduce your overall distance, the pilgrim office had no concern about it when we applied for our Compostela, as long as you still get your minimum 2 stamps per day over this last 100km (Tui to Santiago). But you can also walk if you don't want to take the boat ride. The boat ride goes from Vilanova de Arousa to Pontecesures, which is about 4km before Padrón.
Caldas de Reis is a wonderful pilgrim town, so it also has its charm and lots of history. The spiritual route has been marketed to try and attract pilgrims, and perhaps its "authenticity" could be questioned, but nonetheless it is still a valid route to walk. The boat ride added a touch of adventure and the knowledgeable pilot (his name is Santiago - his boat is the RIB that holds about 12 people), was really great at providing historical information about the many "cruceiros" found at the water's edge, the Torre del Oeste, the mussel farms, the clam fishermen etc.
At the junction where you see the turn to the left to go on the Spiritual Variant the majority of pilgrims continued straight, but the few of us that opted to turn left and try the Spiritual Variant were not disappointed by our choice.
This link provides more complete information:
Walk the Spiritual Variant of the Portuguese Way and discover the origins of the
Camino de Santiago. Enjoy the "Traslatio" by boat, from Vilanova to Padrón.
galiwonders.com