Seaplify
November 14, 2024
Boat Anchoring Essentials Explained: Anchors are essential for boat safety and enjoyment, allowing boaters to secure their vessels in various situations, from weathering storms to exploring points of interest. Choosing a suitable anchorage and understanding anchor principles is crucial for a safe and enjoyable boating experience.
Choosing an Anchorage
Several factors contribute to a good anchorage. Boat Anchoring Essentials Explained emphasizes the importance of considering these factors:
• Water Depth: Ensure sufficient depth for your vessel, considering tides and potential changes in water level.
• Bottom Type: Clay, sand, and mud offer the best holding for anchors. Avoid rocky areas, boulders, and dense weed growth as these substrates provide poor anchoring.
• Protection: Seek protection from prevailing winds, currents, and tides. Assess the anchorage for shelter from predicted winds, especially during storms.
• Boat Density and Anchorage Size: Consider the number of boats already anchored and ensure enough space for your vessel to swing safely without colliding with others.
Types of Anchors
According to Boat Anchoring Essentials Explained, anchors fall into two main categories: heavyweights used for stationary objects like navigation buoys and anchors designed to dig into the seabed for vessels.
Common anchor types include:
• A/P or Fisherman’s: This non-burying anchor is known for its performance in rock, kelp, and grass. However, its holding power to weight ratio is relatively low, and it can foul the cable with changing tides.
• Danforth: This lightweight, compact anchor is a burying type that offers excellent holding power once set. Its flat design makes it easy to retrieve and store.
• CQR/Plough: This versatile anchor performs well in most seabeds due to its hinged shank, which allows it to turn with changing forces without breaking out.
• Bruce/Claw: This anchor sets quickly in most seabeds and remains stable during tide and wind changes. However, it struggles to penetrate weed and grass and has a lower holding power to weight ratio.
Anchor Rode
The anchor rode connects the anchor to the vessel. Boat Anchoring Essentials Explained recommends understanding common rode materials:
• Chain: Heavy, durable, and non-stretchable; chain provides excellent holding power.
• Line: Lightweight and easy to handle, line is prone to chafing and stretches under load.
• Combination: Often used on small yachts, this setup involves chain attached to the anchor and line attached to the chain.
• Wire Rope: Favoured on fishing vessels for its strength and durability.
Capstans and Windlasses
These devices assist in raising and lowering the anchor:
• Capstan: Used on traditional vessels, a capstan relies on crew members turning bars to operate.
• Windlass: Modern vessels commonly use windlasses, which can be manual or powered:
• Pathfinder: Utilises a pawl-rack system with two handles pumped back and forth.
• Playfair: Employs a gear system with handles wound in a circular motion.
Catting the Anchor
“Catting the anchor” refers to the process of hoisting the anchor to hang at the cathead. This involves attaching the chain, rigging a davit, and swinging the anchor overboard. Catting also encompasses bringing the anchor inboard.
Depth Soundings
When we re talking about Boat Anchoring Essentials Explained, determining water depth is crucial for safe anchoring. Traditionally, a lead line with a weighted end is used. Modern vessels utilise electronic depth sounders that emit sound waves to measure depth.
Preparing to Drop the Anchor
Gather necessary supplies, including:
• Hammer or Persuasion Bar: Ensure the windlass’s star is turning smoothly.
• Anchor Ball and Gash Line: Signal that the vessel is anchored.
• T-bar (Pathfinder) or Crank Handle (Playfair): Operate the windlass.
• Flashlight: For nighttime anchoring.
Anchor Scope and Catenary
Scope refers to the ratio of anchor rode length to water depth. Boat Anchoring Essentials Explained advises typical scope recommendations for different situations.
• Swimming Stop: 3:1 scope
• Day Stop: 5:1 scope
• Overnight Stay: 7:1 scope
Catenary, the natural curve of the anchor rode, helps absorb shock loads and maintain the anchor’s hold.
Chain Markings
Chain markings indicate the length of rode deployed. A standard marking system uses coloured markings for specific fathom intervals.
Dropping and Setting the Anchor
Communicate effectively during the anchoring process:
• “Stand up by forward” indicates preparation for anchoring.
• “Let go and veer to x fathoms” instructs the release of the anchor to the specified depth.
• “Dog her there” signals to secure the anchor chain.
Set the anchor ball and turn on the anchor light if anchoring at night.
Monitoring the Anchor
Observe the anchor’s status after setting:
• Report the number of fathoms of chain deployed.
• Note the angle of the chain (short stay or long stay).
• Indicate the direction the chain is leading.
• Confirm the holding status (holding or dragging).
Anchor Watch
Maintain vigilance during anchor watch:
• Use alarms on depth sounders, GPS, or radar to detect changes in position.
• Monitor the chain for signs of dragging.
• Observe wind speed and direction.
• Record all observations in the logbook.
• Stay alert and wake the watch officer if necessary.
Reasons for Anchor Drag
Anchors can drag due to:
• Insufficient scope
• Fouled anchor rode
• Changes in wind or tide
• Unstable bottom conditions
Weighing Anchor
Retrieve the anchor by “heaving short” and then “weighing anchor” with the windlass. Communicate clearly using standard calls:
• “Anchor’s a trip” indicates the anchor has broken free from the bottom.
• “Anchor’s aweigh” signifies the anchor has left the water.
• “Anchor’s in sight” confirms visual contact with the anchor.
• “Anchor’s-a-cockabill” means the anchor is secured at the hawse pipe.
Advanced Anchoring Techniques
• Kedging: Use the anchor to move the vessel in calm conditions or tight spaces.
• Multiple Anchors: Deploy two anchors (bow and stern or two bow anchors) for increased holding power or to restrict swinging in confined anchorages.
• Sea Anchors: Deployed from the bow or stern, sea anchors help maintain vessel stability and control during storms.
Glossary of Key Terms
• Anchor: A heavy object designed to hold a vessel in a fixed position by gripping the seabed.
• Anchor Rode: The combination of chain, line, or wire rope used to connect the anchor to the vessel.
• Scope: The ratio of the length of anchor rode to the depth of the water.
• Catenary: The curve formed by the anchor rode as it hangs between the vessel and the anchor.
• Catting the Anchor: The process of hoisting the anchor and securing it to the vessel.
• Depth Soundings: Measurements of the depth of water beneath a vessel.
• Lead Line: A traditional method of measuring depth using a weighted line with markings.
• Capstan: A vertical drum used to haul in anchor chain or ropes.
• Windlass: A horizontal drum used to haul in anchor chain or ropes.
• Weighing Anchor: The action of removing the vessel by setting and hauling it.
• Sea Anchor: A device deployed from the bow or stern to keep the vessel aligned with the wind and waves during a storm.
• Weighing Anchor: The process of raising the anchor and bringing it on board the vessel.
• Anchor’s Aweigh: A nautical term indicating that the anchor has left the bottom.
• Fathom: A unit of length equal to six feet, used to measure water depth.
• Arming: Applying a sticky substance to the lead weight to check the type of bottom.
• Hawse: The part of a vessel where the anchor chain passes.
• Scope Ratio: The ratio of the length of rode deployed to the depth of the water.
• Whisker Stay: A support for the bowsprit of a vessel through which the anchor chain passes.
Summary
1. The two general categories of anchors are heavy weights and anchors that dig into the bottom. Heavy weights are used for stationary objects like navigation buoys, while anchors that dig into the bottom are used on vessels and combine weight with the ability to penetrate the substrate.
2. The Fisherman’s anchor is a non-burying type with one arm designed to penetrate the seabed and the other standing upright. While it is known for its effectiveness in rock, kelp, and grass, its holding power to weight ratio is low and it can easily foul the cable with changing tides.
3. The Danforth anchor features a hinged stock, allowing the flukes to orient towards the bottom. This burying anchor is highly effective once set, offering significant resistance. Its lightweight and folding design contribute to easy retrieval and storage.
4. Both the CQR/Plough and Bruce/Claw anchors perform well in a variety of seabeds. The CQR/Plough, with its hinged shank, effectively adapts to changes in wind and tide direction, while the Bruce/Claw sets quickly and resists breaking out. However, claw-types struggle in weedy or grassy bottoms and require larger sizes to achieve comparable holding power.
5. Chain rode is heavy, durable, and does not stretch. Line rode is lightweight and stretches but is prone to chafing on rough surfaces. A combination rode, often used on small yachts, combines chain attached to the anchor with line attached to the chain.
6. A capstan is a vertical drum used on traditional vessels, rotated by crew members using bars inserted into holes. A windlass is a horizontal drum typically powered mechanically or electrically.
7. Catting the anchor involves unshackling the anchor, inserting and securing the stock, overhauling the chain, shackling the chain to the anchor, mousing the shackle, rigging a davit, raising and swinging the anchor, lowering it while taking up chain slack, and finally securing it for immediate use or lashing it to whisker stays.
8. Depth soundings with a lead line involve throwing a weighted line with markings from the bow, allowing it to sink to the bottom, and reading the markings on the line when it is vertically aligned beside the thrower. The lead weight can be “armed” with a sticky substance to determine the type of bottom.
9. Scope is the ratio of the length of anchor rode to the depth of the water. Adequate scope ensures that the anchor rode lies along the seabed, maximizing the anchor’s holding power and reducing strain on the boat.
10. Kedging is a technique used to move a vessel using its anchor. The anchor is set at a distance from the boat and then hauled in, pulling the vessel towards it. Kedging is useful in situations with no wind or when maneuvering in confined spaces.
