A Simple guide to Anchoring a Vessel.

1. PLANNING AN
ANCHORAGE
Grunt Productions 2007
A Brief By Lance Grindley

2. PLANNING AN
ANCHORAGE
References:
Any Seamanship Book
GONS Guidelines
Experience
Sailing Directions
Mariners handbook
Port Information Guides
Grunt Productions 2007

3. Grunt Productions 2007
OBJECTIVES
 State the reasons for planning an
anchorage
 Explain the factors to be considered
 Make basic calculations required
 Prepare a simple anchorage plan

4. Grunt Productions 2007
WHY SHOULD WE PLAN?
 Anchor close to final
destination
 Anchor where legal/allowed
 Avoid dangers
 Anchor in a known space
 Room to swing

5. Grunt Productions 2007
HOW DO WE PLAN?

6. Grunt Productions 2007
FACTORS TO CONSIDER

7. Grunt Productions 2007
FACTORS TO CONSIDER
 Draught of Ship
Draught

8. Grunt Productions 2007
FACTORS TO CONSIDER
 Draught of Ship
 Depth of Water
Depth of Water
Draught

9. Grunt Productions 2007
FACTORS TO CONSIDER
 Draught of Ship
 Depth of water
 Tide rise/fall
Draught
Depth of Water
Height of Tide
Draught

10. Grunt Productions 2007
Limiting Danger Line (LDL)
LDL = Draught + Safety
- Min Height
Of Tide
e.g. Draught 6.7m + 2m Safety - 1m H O T = 7.7m

11. ANCHORAGE PLAN
Coastline

12. ANCHORAGE PLAN
Coastline
2.1
5.5
6.7
8.3
6.7
3.3
8.9
2.3
3.5
4.6
6.7

13. ANCHORAGE PLAN
Coastline
2.1
5.5
6.7
8.3
6.7
3.3
8.9
2.3
3.5
4.6
6.7
LDL

14. Grunt Productions 2007
FACTORS TO CONSIDER
 Draught of Ship
 Depth of water
 Tide rise/fall
 As close to land as safety
allows

15. Grunt Productions 2007
FACTORS TO CONSIDER
 Draught of Ship
 Depth of water
 Tide rise/fall
 As close to land as safety
allows
 Safety Swinging Circle

16. Grunt Productions 2007
SAFETY SWINGING CIRCLE
SSC = Length of Ship + Total
length of
cable + Safety
margin
Safety usually 1 Cable (200 yards)

17. Coastline
2.1
5.5
6.7
8.3
6.7
3.3
8.9
2.3
3.5
4.6
6.7
LDL
ANCHORAGE PLAN
Safety Swinging Circle

18. Grunt Productions 2007
FACTORS TO CONSIDER
 Draught of Ship
 Depth of water
 Tide rise/fall
 As close to land as safety
allows
 Swinging Circle
 Holding Ground

19. Grunt Productions 2007
FACTORS TO CONSIDER
 Draught of Ship
 Depth of water
 Tide rise/fall
 As close to land as safety
allows
 Swinging Circle
 Holding Ground
 Navigation Marks

20. Coastline
2.1
5.5
6.7
8.3
6.7
3.3
8.9
2.3
3.5
4.6
6.7
LDL
ANCHORAGE PLAN
Safety Swinging Circle

21. Grunt Productions 2007
Amount = 1½ Depth in
Metres
in Shackles
= 2
Depth in Fathoms
AMOUNT OF CABLE TO USE

22. Grunt Productions 2007
FACTORS TO CONSIDER
 Draught of Ship
 Depth of water
 Tide rise/fall
 As close to land as safety
allows
 Swinging Circle
 Holding Ground
 Navigation Marks

23. ANCHORAGE PLAN
Coastline
2.1
5.5
6.7
8.3
6.7
3.3
8.9
2.3
3.5
4.6
6.7

24. ANCHORAGE PLAN
Coastline
2.1
5.5
6.7
8.3
6.7
3.3
8.9
2.3
3.5
4.6
6.7
LDL

25. Coastline
2.1
5.5
6.7
8.3
6.7
3.3
8.9
2.3
3.5
4.6
6.7
LDL
ANCHORAGE PLAN

26. Coastline
2.1
5.5
6.7
8.3
6.7
3.3
8.9
2.3
3.5
4.6
6.7
LDL
ANCHORAGE PLAN
Safety Swinging Circle

27. Coastline
2.1
5.5
6.7
8.3
6.7
3.3
8.9
2.3
3.5
4.6
6.7
LDL
ANCHORAGE PLAN
Safety Swinging Circle
LG
1
2
3
4

28. Coastline
2.1
5.5
6.7
8.3
6.7
3.3
8.9
2.3
3.5
4.6
6.7
LDL
ANCHORAGE PLAN
Safety Swinging Circle
LG
1
2
3
4

29. Grunt Productions 2007
ANY QUESTIONS?