Lessons
How big is your swinging circle?
Your swinging radius is the cable you've veered plus your own length overall — never half your length — and the circle you actually swing in is twice that radius.
The rule
- You ride to your cable from the hawse pipe — the whole ship is outside the anchor, not half of it.
- Radius = cable veered + length overall.
- The swinging circle is a circle: its size is 2 × radius, not the radius itself.
- Measure clearance from the circle's edge, not its centre.
- Depth and cable type don't enter this sum — only cable veered and length overall do.
Worked example
| Length of cable veered | 192 m |
| Length overall | 244 m |
| Charted depth at the anchor position | 34 m |
| Distance from the anchor position to the charted wreck | 646 m |
- Radius = cable veered + length overall = 192 + 244 = 436 m
- Swinging circle = 2 × radius = 2 × 436 = 872 m
- Clearance to the wreck = distance to wreck − radius = 646 − 436 = 210 m
Common mistake
Using half the length overall, as though the ship swung about her midships.
She doesn't swing about her midships — she rides to her cable from the hawse pipe, so the WHOLE of her length is outside the anchor, and it's the stern that reaches any obstruction closest to her.