Tides, how does it works?

[🇬🇧] I saved this image from 7 January 2014, not because I did not accept this removal from the sea, but because I did not want the Good Surf Good Love connoted with chaos.


I didn’t immediately realize that the brand comes precisely from this chaos, and the full acceptance of this coming and going from storms, tides, winds, and the cyclical Sun – Moon apparitions.

Today I’m posting it, and take the opportunity to explain what factors have combined in this molotov cocktail result.

On this day, there were 12 to 16m of swell, the waves had 24s period and the tide that was alive, at its maximum height was 3.6m.

🟢   And what are the Tides?

Anyone who has spent whole summer days at the beach knows that the tide is coming and going. This action between high tide and low tide is caused by the gravitational action of the moon and sun.


“Tides are periodic fluctuations in sea level and are the result of the attraction of the sun and moon to the liquid particles of the oceans.” At https://tabuademares.com/mares

As the Earth, Moon, and Sun combine in different alignments, generating different types of tides.

Every day there are 4 tides separated by periods of about 6h. That is the length of time it takes the tide to travel between full and empty.

According to the phases of the moon, we can have 2 types of tides: the Spring Tides and the Neap Tides.


Spring tides occur in the Full Moon and New Moon phase when the earth aligns with the moon and the sun.

The Neap Tides – on the First Quarter and Third Quarter  Moon.

In Portugal, the tides range between 0.1 and 3.9m in the case of Spring tides. In the case of Neap Tides, the amplitude variation is very small ranging between 1.4 and 2.5m. 

In other areas of the planet, the amplitudes vary. In some places they are practically nil, in others, the differences are greater.

🌍   This last weekend when the high rainfall combined with a big swell – 7 to 14m and a high period – 17 to 19s (which I didn’t explain here, but will be coming back to it soon) has already done a lot of damage, even in a neap tidal period. Imagine that these were a Spring Tide, it would surely do even more damage.

Note: to check our Portuguese tides check  here: https://www.hidrografico.pt