Avoiding fog off the Portuguese coast in July

[southatlantic]

Originally Posted by boatman61

Many of the ports along the W coast of Portugal are at River mouths and should be treated with caution in weather as the bars can be dangerous when the swell is large.
Yachts and even local vessels/crew are lost attempting to enter every year.. the last 3 years its been rare because of Covid but be aware.
I have entered the Douro a few times with no trouble but once in stay in the Channel and time it with the flood tide.

Good advice, thanks!

[Jackoski]

I have sailed this coast 2 times, the last time without incident. The previous time we caught a net in our prop, it was probably from a small fishing boat but hundreds of feet long, it torn our propshaft coupling so we sailed it for repairs, this was at least 10 miles out. Coming in for repairs into vianna de castella a swell had caused huge beakers into the port without an engine we had no choice but to commit. It was v.scary and riding a series of big breakers is an experience I'd rather forget.

[boatman61]

Viana do Costelo is just past/before the Spanish/Portuguese border, would it not have been wiser to turn back (assuming you were heading S) or, carry on to Baiona which has a much safer entrance and an anchorage along with all the facilities rather than risking lives and boat in dodgy conditions over a bar known for sinking yachts and local vessels.

[seadago]

Originally Posted by southatlantic

Great input, thank you for sharing! We plan to stop at Vigo, Porto and Nazaré, like you did, then Cascais and Lagos. Already got the Windy and Navily apps, they are indeed very useful.
In Porto, did you try Douro Marina? If so, any trouble crossing the Douro bar?

As said by others, most natural harbours on the Portuguese Atlantic are tidal river mouths. Porto case in point. In many of those if not most, there's is a sandbar at the mouth, so big swell can happen with good weather and little wind. In less than favourable conditions Portuguese Prefectura closes the entrance to small vessels so you just can't get in or perhaps worse, out! If visiting Porto is the objective, then I would stop in Matosinhos, just north of the Douro river mouth. Easy access non tidal harbour with a decent marina, and a short bus ride away from centre of Porto.

[Alita49DS]

I have had very thick fog off Cape Finestere. Not off Portugal.

As for fishing net left illegally. This is a major problem not only off Portugal but worldwide. I have had it around the prop off Cabo de Gata and midway between Corsica and Minorca.

A rope cutter is exactly what it says on the tin. It will deal with line. It will NOT deal with sheets of net. You either have to dive, not easy without kit, or lift. A lift should not be necessary unless there has been associated damage.

In the meantime, we should all be supporting the campaign against dumped fishing gear.

[southatlantic]

Originally Posted by Alita49DS

I have had very thick fog off Cape Finestere. Not off Portugal.

As for fishing net left illegally. This is a major problem not only off Portugal but worldwide. I have had it around the prop off Cabo de Gata and midway between Corsica and Minorca.

A rope cutter is exactly what it says on the tin. It will deal with line. It will NOT deal with sheets of net. You either have to dive, not easy without kit, or lift. A lift should not be necessary unless there has been associated damage.

In the meantime, we should all be supporting the campaign against dumped fishing gear.

Thank you for sharing your experience. And yes, abandoned fishing gear is a major problem, not just for boats in general, but especially for the staggering amount of marine wildlife that it kills. Furthermore, once such gear finally decays, it becomes micro-plastics, which creates its own set of environmental problems.

[southatlantic]

Thank you, everyone, for participating and sharing your knowledge. I should be going down this planned route late July/early August. If we encounter fog, I will try staying 15NM or so from the coast to avoid it (as well as avoiding the fishing pots and nets). I will then report back on the results here.

Fair winds

[southatlantic]

OK, so here was my experience, in mid-August: Left Vigo under a very thick fog. Navigating in the Ria, even with radar and AIS was no fun, given the intensity of boat traffic and the large number of bivalve farm structures. Fortunately, they do show up well on radar.

After leaving the Ria, we went further offshore, about 6NM. The fog did not completely disappear, but got a lot better, I would guess 80% better, allowing for visual navigation without much trouble.

There were a lot of fishing buoys, even at that distance from the coast and about 100m depth. We had to keep a constant watch at all times, but, given that, were able to see them in time to avoid them, so did not bother going any further offshore. We got to Porto with no trouble and the fog was light by the time we got there.

The following day we went from Porto to Nazare with very good visibility, so stayed closer to the beautiful coast of Portugal (about 4NM). Lots of dolphins, but also lots of fishing buoys. From Nazare to Cascais, excellent visibility and somewhat fewer fishing buoys. Really beautiful coastline.

So, in answer to the original question, this one data point points to yes, you can avoid summer fog in that area by sailing further offshore than you normally would.
Fair winds!

[Jenneau Owner]

I sailed down the Portuguese coast some years ago en rout from UK to the Med.
If you have time there are some great off the beaten track harbours and anchorages.
By far the biggest problem we found were numerous fish farms and FORESTS of lobster pots.
Day light trips from harbour to harbour tended to be 55-65 NM per day which meant early starts.
Highlights of the trip were La Coruna(Spain), Porto, and Cadiz( again Spain)

[Borja]

Originally Posted by goboatingnow

Fog is not a problem except in the shoulder seasons.

Not quite, coastal fog is a big problem on the Iberian northwestern coast during Summer. It's mostly a Summer phenomenon.

For future reference, this is advective fog, triggered by the upwelling caused by the nortada, the Portuguese northerly, and the Coriolis effect - warm surface water is dragged offshore and replaced by deeper cold water. Without clouds, land temperature raises faster, and the sea breeze slowly drags warm westerly over that cold water, creating the coastal fog. Then it dissipates as temperatures over water and winds pick up later in the morning.

It's the exact same phenomenon that happens in the Bay Area, the San Francisco Summer fog.

It becomes much rarer south of Tejo estuary, due to Cape Carvoeiro and the Lisbon/Setubal canyons cutting off the upwelling.

The ways of avoiding it are sailing only during the afternoon or going offshore of the fog (which can be pretty variable). I guess periods of weak northerlies and relatively warm coastal seawater will mean a lower probability of advective fog but that's rare.

Glad you enjoyed the trip OP - it's where I'm from but aside from a couple of spots for kiting and dinghy sailing, definitely not my favourite grounds (except the Rias, which are awesome) - but to each their own.

[southatlantic]

For additional evidence that one can (at least sometimes) avoid summer fog off the Portuguese fog, by moving away from the coast, here is the end of a thick fog bank, 11NM offshore. I took this photo two days ago, off the coast of Sines.