Don’t Be Left High & Dry: Understanding Tides & Currents
We’ve all seen that unfortunate image of a beautiful boat grounded in the sand somewhere, the result of changing tide conditions. No one wants to get caught in this type of embarrassing and potentially costly scenario. Understanding how tides and currents impact your boating activities, and applying what you know to your local waterways, will be invaluable in helping you successfully navigate and plan for a safe and enjoyable boating experience.
First, let’s share the definition of these two important terms.
Tide is the flow of sea water in and out to shore due to the pull of gravity of the sun and moon.
No matter where you boat anywhere around the world, tides are predictable. Tides are expressed as a number relative to the height of the water in feet measured from a “zero” line, for example 1.8 or -0.5.
Current is the speed of the flow of water that creates a change in the height of the tide.
As the time for high tide approaches, the sea water begins to flow toward shore, first slowly and then with increasing speed (CURRENT) in the middle of the cycle, and then with less speed toward the end of the cycle.
Once HIGH tide is reached, the flow “in” stops, followed by “slack water.” Soon, the process starts in the opposite direction and the flow “out” begins toward LOW tide.
Again, the water begins to move slowly out to sea, with CURRENT/SPEED of the flow INCREASING during the middle of the cycle and the subsiding again as the flow stops and the water reaches “slack water or/tide.”
Tides and currents are very important to understand as they affect boat handling, particularly during beaching a boat or docking activities.
BEACHING – If you plan to enjoy a family picnic at a local island, for example, you’ll want to be well aware of tide conditions. Check in advance to know the time for high or low tide so you can watch you anchor on shore and be well prepared to adjust the boat’s position as needed. Paying to tow a “high and dry” boat off the beach as noted can be a very costly proposition. In addition, chasing a boat that has floated free and is suddenly loose in the outgoing tide and current is equally challenging and can be very dangerous.
DOCKING – Ever returned to the dock after a great day on the water, only to feel out of control due to treacherous currents? Or, perhaps you’ve planned a great stop for lunch at one of the popular dockside restaurants located near an inlet … upon approach, you’ve faced some very tough current conditions!
Understanding the day’s forecast for high and low tide and wind direction in advance will help you in these conditions to dock and maneuver like a pro!
Strategically, you will want to plan to approach the dock INTO THE FORCE OF THE WATER (current) OR WIND. If the tide/current is coming in, the wind could be from the opposite direction…..you will need to determine which is stronger and make your approach in that direction. TIP: usually “current trumps wind.”
If you encounter these types of challenging conditions, we strongly suggest that you STOP for a moment with your boat perpendicular to the dock and observe which direction your boat is being pushed. You want to plan to dock with the bow of your boat facing INTO THE FORCE.
CURRENT/SPEED – the greater the separation between the high and low tides in height, the faster the current will be as the water flows in or out.
For example: if the high tide is charted to reach 2.5 (that’s feet above mean low water) at 8:00 am and the low tide is expected to be -.5 (that’s feet below mean low water), at 4:00 pm the change is THREE full feet. When you’re ready for lunch at noon to 1:00 pm, there will usually be significant CURRENT/SPEED to push your boat around. To exercise full control, you would want to approach the dock with your bow into that current.
Smart boaters will take the time to thoroughly familiarize themselves with tide and current conditions before heading out for the day. The more you learn and practice proven strategies for success, the more enjoyable will be your boating activities!
AVAILABLE APPS: There are a few easy to use APPs to help you monitor tides and current conditions: “Sea Tow” offers a free APP and “Hi Tide” is available to download for $1.99.
BOAT SAFE. HAVE FUN!