Prerequisites for the RYA Yachtmaster Coastal and Offshore exams include an amount of tidal miles. At least 400 for the YMC and 1250nm for the Offshore.
If all your sailing has been in UK waters then you can consider all of your miles as tidal. But what about if sailing in the Med makes up a good amount of your mileage?
For the purposes of your YMC and YMO exam prerequisites, the Mediterranean is considered non-tidal as in many areas the tidal range will not exceed one foot or 0.3 metres. So they do not count as tidal miles.
However, that doesn’t mean that by definition the Mediterranean is non tidal, because it still has a tidal range, albeit a small one.
The Mediterranean is a semi-enclosed sea that is connected to the Atlantic Ocean through the Strait of Gibraltar. The nature of the surrounding geography means that the Mediterranean is micro-tidal with a tidal range of less than two meters.
Tidal characteristics of the Mediterranean Sea
The tides in the Mediterranean Sea are primarily diurnal, meaning that there is only one high tide and one low tide every 24 hours. Compare this to the Solent, which is semi-diurnal, plus has a high tidal range and double highs which makes it a perfect place to learn – if you can get to grips with the tide in the Solent then anywhere else will seem ‘easy’ by comparison.
In the Mediterranean the tidal range is generally small, with a mean tidal range of around 30 centimetres. However, there are some places in the Mediterranean Basin where the tidal range can be much larger, such as the Gulf of Gabes in Tunisia and the northern Adriatic Sea.
The tidal range of the Mediterranean is also affected by the Strait of Gibraltar. This narrow waterway is the only connection between the Mediterranean and the Atlantic Ocean. It’s just eight and a half miles wide at its narrowest point so plays a significant role in the tidal dynamics of the Mediterranean. It means there is a difference in the water levels between the Atlantic and Mediterranean.
Comparing the two, the Atlantic Ocean has a higher tidal range than the Mediterranean due to its larger surface area and exposure to open ocean winds.
Tidal energy is also affected by the topography of the sea floor in the Mediterranean, which can amplify or dampen tidal waves.
As a rule of thumb, you can expect to experience a larger tidal range in the western Mediterranean versus the eastern Mediterranean.
The other thing that can influence the height of tide in the Med (and anywhere in the world for that matter) is the air pressure which has a direct influence on the sea level. A high pressure weather system has the effect of lowering the sea level. Conversely, a low pressure system has the affect of increasing the sea level.
The post Is the Mediterranean Tidal? appeared first on Sailing Blog.