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Seamanship. Chapter 6 Anchoring, Mooring and Rafting. Learning Objectives. This session is intended to acquaint you with: anchor types and equipment anchoring techniques locations for effective anchoring mooring and rafting. Anchoring. The skill of securing the vessel to the bottom.
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Seamanship Chapter 6 Anchoring, Mooring and Rafting
Learning Objectives • This session is intended to acquaint you with: • anchor types and equipment • anchoring techniques • locations for effective anchoring • mooring and rafting
Anchoring • The skill of securing the vessel to the bottom
Many boaters carry several anchors of different sizes and types What do you need?
Mushroom Anchors • Mooring Dinghy anchor
Grapnel closed open
Anchor Rode • Rode is the entire length of anchor line or chain between the boat and the anchor
Nylon (et al) Less costly Lighter in weight 20% or greater stretch Shock absorber Easier to work with Heat stress failure Wear and abrasion Some UV damage Chain Expensive Heavy and heavier Rugged Resists wear and abrasion Deep catenary Holds bottom Does not stretch Non-absorbing May need a hoist May bow down trim the boat Corrosion potential Gloves Nylon vs. Chain
Anchor Chain • Strength and weight differences
Correct Anchor Size & Weight • Check your manufacture’s recommendations • Under what conditions will the anchor be used? • Storm anchors – increase the weight and size of rode.
How much Chain and Line? • Typical anchor system • Chain at anchor • Line to boat
Scope >>
Scope • Line/Chain combo • 7:1 nominal • 10:1 storm • 5:1 light conditions • All Chain • 3:1 – 5:1
Why Chain? • Prevents chafe on bottom • Hold anchor stock horizontal • Enhances catenary • How long? • 1/2 to full length of boat for combo • More is better
Catenary - Line • Natural catenary – provides cushion • Straightens under wind and wave conditions
Catenary - Chain • Chain contours bottom • Peels from bottom under wind and wave conditions
Anchor Sentinel • Sentinel – weight deployed on anchor rode • Alters catenary to flatter position • Sentinel suspended and held in place by line: “Preventer” (red)
Snubber • Snubber – section of line allowing chain to loop • Serves as a “shock absorber”
Anchor Windlass Lock Switch
No Anchor Warnings No Anchor Areas
Anchoring >>
In tight quarters two anchors may be required to control swing Two Anchors
Scope 7 to 10:1 30° to 45° Two Bow Anchors
In confined space two bow anchors can be used Bahamian Mooring Plan for your swing room
Same basic consideration for any anchoring situation Overnight Anchoring
Raftup • Socialization on the water • Boaters can safely move from boat to boat • Planning and permission required
Rafting in a Circle Good manners and courtesy are important during raftups.
End Anchoring, Mooring and Rafting