What does "slack tide" mean?

Slack tide, or slack water, is the brief period in a tidal cycle when the water is momentarily still, with little to no current, as it transitions from an incoming (flood) tide to an outgoing (ebb) tide, or vice versa. This calm occurs twice daily, around high and low water, offering a window of calm where currents are weakest, making it ideal for boating, fishing, and swimming in some conditions, though its timing and intensity vary greatly by location.

How long does slack tide last?

In some spots, slack tide can last for 30 seconds, while it might last for more than 30 minutes in others. Using our same example, although the chart states the tide change is 1:30, the tidal current might not get moving until 2. The period between 1:30 and 2 is slack tide.

Why is it called slack tide?

Why the name Slack Tide? 🤔 Slack tide is that brief, peaceful moment between the ebb and flow, when the water is calm, the current is still, and everything is in perfect balance. Our name reflects how we want you to feel here: relaxed, unhurried, and fully immersed in the experience.

Is slack tide the best time to dive?

There's a general rule of thumb divers follow: Slack tide, about an hour before high or low tide, is often the best time to dive with little or no current. Having a baseline understanding of how tides work allows you to layer in local knowledge to specific sites.

Where does slackwater usually occur?

Slack water occurs twice during a tidal cycle. In coastal waters (flow influenced by friction and boundaries), one slack water occurs closer to low water (low-water slack tide, LWS) and another slack water occurs closer to high water (high-water slack tide, HWS).

Understanding "Slack Tide": A Natural Phenomenon

What happens during slack tide?

A slack tide is the brief period in a body of tidal water when the water is completely unstressed, and there is no movement either way in the tidal stream. It occurs before the direction of the tidal stream reverses.

How long is slack water after high tide?

The exact time of 'Slack' is unique to every beach, but on an open coast it is generally around 2 hours before high tide and 4 hours after high tide [+/- 1 hour for local anomalies].

How did Chris survive 40 minutes without oxygen?

Chris Lemons survived nearly 40 minutes without oxygen due to a perfect storm of factors: his body tissues were supersaturated with oxygen from the heliox breathing gas used in saturation diving, the freezing North Sea water rapidly cooled his body and brain, drastically slowing his metabolism and oxygen demand, allowing him to enter a state of suspended animation until rescued. Experts call his survival inexplicable, with rapid brain cooling being key to preventing brain damage, making it a miraculous convergence of physiology and environment.
 

How to tell if it's slack tide?

It's the period during which the water is momentarily still - there is no movement either toward or away from the shore. It occurs when the tidal stream pauses just before it reverses direction, transitioning from the incoming flow (flood) to the outgoing flow (ebb) or vice versa.

What is the 50-90 rule for tides?

The 50/90 rule (or 50/90/100 rule) is a simple guideline for estimating tidal current speed, stating that an hour after slack water (0% flow), the current reaches 50% of its max speed, then 90% by the second hour, and 100% (maximum) at the third hour, before slowing back down in the same pattern (90%, 50%) until the next slack water in the sixth hour, indicating a cycle of roughly 0/50/90/100/90/50/0% flow over six hours. It's a useful rule of thumb for kayakers and sailors for basic planning, though it's less accurate in complex areas like estuaries compared to official charts.
 

What is the slack tide rule?

The two hours surrounding the high/low tide is what is referred to as the 'slack tide', when not much water is moving. (1/12 + 1/12). Weather also impacts the tides.

What is the best tide to dive in?

In general, it is always best to dive on a slack high tide. This is when the fresh cleaner water from the sea is coming in and is moving the least in the tide cycle. Be sure to check the closest tide chart to where you are intending to dive.

How does slackwater affect boating?

During these moments of tranquility, typically lasting only about 30 minutes to an hour, you might notice how different the landscape appears. Boats bob gently without being swept away by strong currents; fishermen often take advantage of this serene time to cast their lines into waters that are otherwise tumultuous.

What is a Dodge tide?

This is a local South Australian term for a neap tide with minimal rise and fall over the course of a day or two. While very 'flat' neaps (see neap tide) occur in a number of locations worldwide, the term 'dodge' is used only in South Australia.

How long does slack tide take?

The time of slack water, particularly in constricted waters, does not occur at high and low water, and in certain areas, such as Primera Angostura, the ebb may run for up to three hours after the water level has started to rise. Similarly, the flood may run for up to three hours after the water has started to fall.

What is the tide in Dubai?

Tides for Dubai

Current tide height is 0.58 m and the water level is falling. Next low tide will be in 2 h 2 min. First low tide is at 05:45 (Yesterday) with height of -0.66 m, and the second low tide is at 18:29 (Yesterday) with height of -0.67 m. First high tide is at 12:09 (Yesterday) with height of 0.76 m.

Why did Stephen wait 20 seconds Alessia?

Many got slightly disoriented, but thankfully without any incident. That is one of the main reasons why Stephen decided to do a VWT dive down to the bottom and wait there for Alessia's exit, to optimize her level of safety and be ready to guide her to the ascent dive line if necessary.

What's the longest someone has gone without oxygen and lived?

A few minutes without oxygen can be fatal, so we have an involuntary reflex to breathe. But freediver Vitomir Maričić recently held his breath for a new world record of 29 minutes and three seconds, lying on the bottom of a 3-metre-deep pool in Croatia.

Is getting the bends painful?

Type I decompression sickness (less severe)

The less severe type (or musculoskeletal form) of decompression sickness, often called the bends, typically causes pain.

What is the rule of 6 for tides?

The Tide Rule of Sixths (also Rule of Twelfths) is a navigational guideline that estimates tidal height changes over a six-hour cycle by dividing the total tidal range (difference between high and low tide) into twelve equal parts, with the water rising or falling fastest in the middle hours (3rd and 4th) and slowest at the beginning and end. In the first hour after low tide, it rises 1/12th; the second hour, 2/12ths; the third and fourth, 3/12ths each; the fifth, 2/12ths; and the sixth hour, 1/12th, reaching high tide. This provides a quick, rough estimate for sailors but isn't perfectly accurate as actual tides vary by location and weather.
 

What's the highest tide ever recorded?

The highest recorded tide level was 53.6 feet (16 meters) recorded at Burntcoat Head, Nova Scotia. For October, we've added an iOS 🍎 home tide widget option and added a tide tile to the current conditions update so you can better know before you go. 🤙🏼

What is a dead tide?

Dead tide: If the earth-moon connection line is perpendicular to the earth-sun, this is called the first quarter or last quarter. The associated tide is called dead tide, which has a lower high water level and a higher low water level than normal, so that the tidal difference is smaller.