An anchor swing circle is the area in which a boat can move around its anchor. Calculating the radius of this circle is crucial for ensuring that the boat remains in a safe zone, avoiding collisions with other objects or boats. The radius of the swing circle depends on the length of the anchor rope and the vertical drop distance from the boat to the seabed.

**Formula**

The formula to calculate the radius of the anchor swing circle is:

**R = sqrt(L² − D²)**

Where:

**R**is the radius of the swing circle.**L**is the length of the anchor rope.**D**is the drop distance.

**How to Use**

- Measure the length of the anchor rope from the boat to the anchor.
- Measure the vertical drop distance from the boat to the seabed.
- Enter these values into the calculator.
- Press the “Calculate” button to get the radius of the swing circle.

**Example**

If the length of the anchor rope (L) is 100 meters and the drop distance (D) is 30 meters, using the formula:

R = sqrt(100² − 30²)

R = sqrt(10000 − 900)

R = sqrt(9100)

R ≈ 95.41 meters

The radius of the anchor swing circle is approximately 95.41 meters.

**FAQs**

**What is an anchor swing circle?**

An anchor swing circle is the area around the anchor where a boat can move due to wind, currents, and tide while anchored.**Why is it important to calculate the anchor swing circle?**

Calculating the anchor swing circle is important to ensure that the boat does not collide with other objects or boats in the vicinity.**What factors affect the size of the anchor swing circle?**

The size of the anchor swing circle is affected by the length of the anchor rope and the vertical drop distance from the boat to the seabed.**Can I use this calculator for any type of boat?**

Yes, this calculator can be used for any type of boat, as long as you have the necessary measurements.**What is the difference between anchor swing circle and scope?**

The scope is the ratio of the length of the anchor rope to the depth of the water, while the anchor swing circle refers to the area around the anchor where the boat can swing.**Is it possible to have a negative radius?**

No, a negative radius is not possible. If the calculation results in a negative number, recheck your input values.**What units should I use for the measurements?**

You can use any units (meters, feet, etc.) as long as the same units are used consistently for both the length and drop distance.**Does the anchor swing circle change with tides?**

Yes, the anchor swing circle can change with tides, as the drop distance (D) may vary with changing water levels.**How do wind and current affect the anchor swing circle?**

Wind and current can cause the boat to move within the swing circle, but the calculated radius remains the same.**Can I calculate the anchor swing circle without the drop distance?**

No, the drop distance is essential for accurately calculating the radius of the swing circle.**Is the anchor swing circle always a perfect circle?**

Ideally, it is, but in practice, factors like wind direction and current can slightly alter the shape.**What should I do if my boat is too close to another boat within the swing circle?**

If another boat is within your swing circle, you should consider repositioning your anchor or choosing a different anchorage spot.**Can I use this calculator in freshwater and saltwater?**

Yes, this calculator works for both freshwater and saltwater conditions.**How often should I calculate the anchor swing circle?**

It is advisable to calculate the swing circle each time you anchor in a new location.**What if my anchor rope is too short?**

If your anchor rope is too short, you may need to increase its length to ensure a safe anchor swing circle.

**Conclusion**

Calculating the anchor swing circle is vital for safe anchoring, especially in crowded or obstacle-filled waters. By using the Anchor Swing Circle Calculator, you can easily determine the safe area around your anchor, ensuring that your boat remains secure and avoids potential collisions.