1. PLANNING ANPLANNING AN
ANCHORAGEANCHORAGE
Grunt Productions 2007
A Brief By Lance GrindleyA Brief By Lance Grindley

2. PLANNING ANPLANNING AN
ANCHORAGEANCHORAGE
References:
Any Seamanship Book
GONS Guidelines
Experience
Sailing Directions
Mariners handbook
Port Information GuidesGrunt Productions 2007

3. Grunt Productions 2007
OBJECTIVEOBJECTIVE
SS
 State the reasons for planning anState the reasons for planning an
anchorageanchorage
 Explain the factors to be consideredExplain the factors to be considered
 Make basic calculations requiredMake basic calculations required
 Prepare a simple anchorage planPrepare a simple anchorage plan

4. Grunt Productions 2007
WHY SHOULD WEWHY SHOULD WE
PLAN?PLAN?
 Anchor close to finalAnchor close to final
destinationdestination
 Anchor where legal/allowedAnchor where legal/allowed
 Avoid dangersAvoid dangers
 Anchor in a known spaceAnchor in a known space
 Room to swingRoom to swing

5. Grunt Productions 2007
HOW DO WE PLAN?HOW DO WE PLAN?

6. Grunt Productions 2007
FACTORS TOFACTORS TO
CONSIDERCONSIDER

7. Grunt Productions 2007
FACTORS TOFACTORS TO
CONSIDERCONSIDER
 Draught of ShipDraught of Ship
Draught

8. Grunt Productions 2007
FACTORS TOFACTORS TO
CONSIDERCONSIDER
 Draught of ShipDraught of Ship
 Depth of WaterDepth of Water
Depth of Water
Draught

9. Grunt Productions 2007
FACTORS TOFACTORS TO
CONSIDERCONSIDER
 Draught of ShipDraught of Ship
 Depth of waterDepth of water
 Tide rise/fallTide rise/fall
Draught
Depth of Water
Height of Tide
Draught

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

11. ANCHORAGE PLANANCHORAGE PLAN
Coastline

12. ANCHORAGE PLANANCHORAGE 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 PLANANCHORAGE 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 TOFACTORS TO
CONSIDERCONSIDER
 Draught of ShipDraught of Ship
 Depth of waterDepth of water
 Tide rise/fallTide rise/fall
 As close to land as safetyAs close to land as safety
allowsallows

15. Grunt Productions 2007
FACTORS TOFACTORS TO
CONSIDERCONSIDER
 Draught of ShipDraught of Ship
 Depth of waterDepth of water
 Tide rise/fallTide rise/fall
 As close to land as safetyAs close to land as safety
allowsallows
 Safety Swinging CircleSafety Swinging Circle

16. Grunt Productions 2007
SAFETY SWINGINGSAFETY SWINGING
CIRCLECIRCLE
SSC = Length of Ship + TotalSSC = Length of Ship + Total
length oflength of
cable + Safetycable + Safety
marginmargin
Safety usually 1 Cable (200 yards)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 PLANANCHORAGE PLAN
Safety Swinging Circle

18. Grunt Productions 2007
FACTORS TOFACTORS TO
CONSIDERCONSIDER
 Draught of ShipDraught of Ship
 Depth of waterDepth of water
 Tide rise/fallTide rise/fall
 As close to land as safetyAs close to land as safety
allowsallows
 Swinging CircleSwinging Circle
 Holding GroundHolding Ground

19. Grunt Productions 2007
FACTORS TOFACTORS TO
CONSIDERCONSIDER
 Draught of ShipDraught of Ship
 Depth of waterDepth of water
 Tide rise/fallTide rise/fall
 As close to land as safetyAs close to land as safety
allowsallows
 Swinging CircleSwinging Circle
 Holding GroundHolding Ground
 Navigation MarksNavigation 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 PLANANCHORAGE PLAN
Safety Swinging Circle

21. Grunt Productions 2007
AmountAmount = 1½= 1½√√ Depth inDepth in
MetresMetres
in Shacklesin Shackles
= 2= 2√√
Depth in FathomsDepth in Fathoms
AMOUNT OF CABLE TOAMOUNT OF CABLE TO
USEUSE

22. Grunt Productions 2007
FACTORS TOFACTORS TO
CONSIDERCONSIDER
 Draught of ShipDraught of Ship
 Depth of waterDepth of water
 Tide rise/fallTide rise/fall
 As close to land as safetyAs close to land as safety
allowsallows
 Swinging CircleSwinging Circle
 Holding GroundHolding Ground
 Navigation MarksNavigation Marks

23. ANCHORAGE PLANANCHORAGE 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 PLANANCHORAGE 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 PLANANCHORAGE 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 PLANANCHORAGE 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 PLANANCHORAGE 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 PLANANCHORAGE PLAN
Safety Swinging Circle
LG
1
2
3
4

29. Grunt Productions 2007
ANY QUESTIONS?ANY QUESTIONS?