Awareness of the tides when sailing can mean the difference between a safe passage and a disaster. Researchers have recorded the most extensive tidal range in the world in the Bay of Fundy, Canada. The difference between low tides and high tides here can be up to 16.3 meters (53.5 feet).
Tidal watches allow you to monitor the rise and fall of the tide through a simple tide indicator on the watch’s face. This article tells you how to use a tidal watch.
Let’s take a quick look and answer the question of what is a tidal watch and how it can help you sail more safely.
What Is a Tide Watch
Tidal patterns and heights are highly complex subjects and impossible to show in detail on a watch. However, a tidal watch can display the ebb and flow of the tide to give a visual representation of the tidal movement. These are common features among the best sailing watches.
As long as the tidal watch is synchronized accurately with the local tide times, you can use it to keep an eye on the local tide movement.
To understand how a tide watch works so you can accurately read a tide, we need to know a little about the causes of the tides.
Why Is A Tide Watch Useful
If you only sail in areas with little or no tide, you might wonder why they are helpful. As we mentioned earlier, tides can change the height of water in a particular area by many meters. In addition, the tidal current through a specific area can be very high.
I once sailed on the west coast of Scotland. There are sizeable tidal height variations here and areas where the current can flow faster than your boat can motor under engine power. If you approach Kyle Rhea at the wrong time, the current can be up to eight knots against you!
On a boat I learned to sail on, a Contessa 38, the maximum speed with the engine was about 6 knots, so we’d be going backwards! This can be equally important if you’re participating in a long-distance sailing race.
How Does a Tide Watch Work
What Causes The Tides
The gravitational pull of the moon and sun cause our tides. As the Earth spins and the moon phase and the sun change position, their gravitational force pull the water towards them. As the moon is closer to Earth, its influence is double that of the sun. However, the pull is increased further when the sun and moon align. This is the main cause of a tidal force.
It is also worth noting that land masses, the contour of the seabed, atmospheric pressure, and coastal features also influence the tides affect. These features, along with the shape of the Earth, account for the differences in tide heights worldwide.
For this reason, these watches track the moon’s gravitational pull as the Earth rotates. This tidal information is on its watch face sometimes in the form of the current lunar day and/or lunar month, like full moon, new moon, etc.
Tide tables give predicted high and low water times for a specific port or location. This is important for measuring the effects of falling tide forces, an outgoing tide, and more. As you can see from the example below, there is detailed information for each day, including the lunar cycle. The black circle on the table means a new moon, while the white circle means a full moon.
Although thousands of sites have tide tables, there are many thousands more that do not. You must use a secondary port tide table if your location is not listed. Using the home and secondary port data, you can calculate your area’s predicted high and low tides.
It isn’t possible to display all the tide table information on an analog watch, so what information do they show?
How Does A Tide Watch Display The Tides?
With the complex nature of tides, the information shown on an analog tide watch will be limited. The most common analog display type is a small circular face with a single sweep hand. Digital displays can offer much more information, which is why they’re some of the best sailing watches you can own; we will discuss those later.
The sweep hand indicates where you are in the current cycle, moving from high tide through the ebb tide, low tide, flood, and then back to high tide.
But how does your tide watch know when high tide occurs?
Synchronizing Your Tide Watch
To have an accurate tide watch, you must synchronize your tide watch to the local port you wish to use. By consulting an online tides guide or using printed tide guides, determine the next high tide for your local port.
When the high tide is reached, you push the set button on the watch to bring the sweep hand to the 12 o’clock position.
Tide Watch Accuracy
The time between high and low tide is approximately 12 hours and 25 minutes. This is an average, but on different days it will vary. It’s essential to check the synchronization of your tide watch regularly and at least monthly.
How Do You Read a Tide Watch
We will concentrate on analog tide watches here, as digital tide watches can have a range of displays particular to the model or brand.
As we described earlier, analog tide watches use a circular display with a single sweep hand.
High tide is shown at the 12 o’clock position. As the hand moves clockwise, it indicates an ebb tide, with the 6 o’clock position showing when low tide occurs. As the sweep hand continues moving clockwise, it shows the flood tide until returning to the 12 o’clock point at the next high tide.
The full rotation of the sweep hand takes 12 hours and 25 minutes, the approximate time between high and low tides.
With an analog tide watch, it is straightforward to see where you currently are in the next tide cycle. If the sweep hand is on the right, the tide is ebbing, and if on the left, it is flooding. At 12, it is high tide, and at 6, it is low tide.
Between the 12 o’clock and 6 o’clock positions, the display is segmented on each side to indicate the hours between high tides and low tides.
The description above refers to analog tide watches. With digital watches, there is the opportunity to display additional information, which can be important if you plan on participating in a regatta and are in need of a good sailing race watch.
Analog Tide Watch vs. Digital Tide Watch
Until now, we have talked mostly about analog tide watches. But we can’t ignore the digital revolution. Both types of watches used for tides will be waterproof, display standard features such as the time, and offer additional information. Digital tide watches can offer much more information compared to an analog equivalent.
However, the flip side is that too much information can be confusing on a small display. Analog tide watches have the advantage that a quick glance will give you the critical information via tide indicators you’ll need.
Analog Tide Watches
Analog tide watches tend to have a traditional look, and many people wouldn’t realize it had additional features.
- Very easy to use
- Traditional look
- It only shows limited information
- Manual synchronization
Digital Tide Watches
Many people prefer an analog over a digital watch despite their practicality and affordability. It is, of course, possible to buy a digital sailing watch that displays sweeping hands, but they still don’t have the look and style of an analog. That alone may sway your decision.
- Detailed incoming tide information
- Pre-programmed tide locations
- Easy to change the home port
- Automatic updates with GPS
- Not everyone’s style
- Maybe too much information
- More difficult to read at a glance
Both digital and analog watches will give you the information you need, so selecting between them is a personal choice.
Tide watches offer a quick and straightforward way of checking where you are in the tidal cycle via a tide indicator, particularly on an analog sailing watch. This can be very useful when approaching areas with a fast-flowing current or a harbor you can only enter at high tide.
While digital sailing watches can offer far more information, the display may not be as quick to read as an analog version. So be sure to choose a type of watch that best suits your needs when monitoring tide data.