Anchoring
There are rapid developments in designs
of anchor. Modern 'roll bar' types like the Rocna and Bugel
are reputed to be a significant improvement on the older designs
Types of Anchor
What to consider when preparing to
anchor:
- Depth of water:
3 - 4 metres is a normal minimum except in a flat calm. Also
consider it you are over mud, sand or rock Setting a few inches into
mud is not a problem in calm conditions.
- State of the tide and future high and low water
heights.
- Type of seabed:
mud and sand are good; avoid pebbles, rock, weed, foul ground, soft
sand. Clay is good holding but
difficult to retrieve the anchor.
- Length of cable required:
4 times max depth for chain, 6 times max depth for warp.
Use nylon warp (plaited or twist) for its stretch properties.
In shallow water and high winds let out 10 times depth with chain and
warp. Although chain is
excellent for its weight and catenary properties, it does not stretch and can snatch
the boat and the anchor in waves.
- Shelter from wind and waves;
Weather forecast - future strength and direction; Consider
two anchors if necessary.
- Ease of escape if wind should shift.
- Other boats and their swinging circles; motor
boats are more affected by wind, long keel boats by the tide or current.
- Use of an anchor buoy to ease retrieval.
Process
(this can be done under sail or engine - if under sail push out the boom to
reverse)
Set
up a signal system between helm and crew to avoid unseemly shouting!
- Check
the present and future depth in your selected position.
- Lay
out required length of cable on deck and free the anchor to hang over the
bow ready to drop.
Check the shackle is secured, preferably with seizing wire.
- Bring
the boat to a stop into current and/or wind.
Other boats may indicate the correct direction, but motorboats may
lie differently to sailing boats.
- Reverse
gently while letting run the chain. Avoid
dropping all the chain in a pile on the sea bed.
- Check the anchor is biting:
the chain / warp will go tight. Put
on more power in reverse to check the anchor is bedded in.
Use a transit on a mark on your beam to ensure you have stopped.
- Re check the transit or take a bearing on a
convenient mark. Check this at
intervals to ensure you are not dragging.
- Set your anchor ball or turn on your anchor
light.
- Check swinging circles of other boats from
time to time.
- Set anchor alarm on the GPS (note sometimes
these are very faint, they will not wake you up!)
- Check again if the wind gets up.
- Cautious skippers check again when the tide
turns.
Recovery
- Motor forward slowly while chain is
recovered. Indicate direction of anchor and required speed to helm
from the bow. Do not over run the anchor.
- Signal to helm when anchor is just below the
surface of the water.
- If anchor is covered in mud or weed motor
forward slowly to clean it.
- Have a bucket of sea water available to wash
off the chain and anchor.
- Chain may need feeding from below if it tends
to stack up in the chain locker.
- Fasten the anchor securely in the well.
Updated 15th June 2011
