Slipping at Anchor

[nauticalrich]

Here''s a good one. Anchored all night and was rough but ok. Then there was calm and a wind change in the morning. Someone was looking out for us because the wind change pushed out to sea and not on the rocks and we were awake when we slipped at anchor.

So I pulled the Force anchor up without any problem at all and found the chain wrapped around the flukes. Good reason for it not to seat.

During the calm the chain must have wrapped around it and when the wind picked up some how it must have broken the anchor lose.

Any advice on how not to do this again?
By the way I have a GPS map 162 which I just found has a anchor drag alarm. Unfortunately this is a new Gps for me and I didn''t realize it had that option. Wonder if it really works?

[sailingfool]

The GPS should work, although you''ll get a lot more false warnings than real.

As to what to do to avoid the problem, set two anchors and sleep well. See articles on Sailnet or other sources like Chapmans as to technique involved.

[mcain]

The 162 has an anchor alarm, but if I remember right, the units are nm, in hundredths. So, each increment is about 50 ft. The alarm is also fairly quiet, so if the 162 is in the cockpit, you will probably not hear it.

[GordMay]

The chain would not likely have fouled a buried anchor fluke - ergo, it was never properly set. Solution: Ensure you set your anchor, prior to cocktails etc.
Your (commercial) GPS will not stand an effective anchor watch. It''ll either "false" alarm, or fail to alarm (depending upon your setting).
OMO
Gord

[nauticalrich]

When we pulled into anchor we did set the anchor, putting boat in reverse and backing off. It held through some rough waves and wind for a good portion of the night and it was only in the morning and when the wind shifted when we slipped.
I have no idea when the wind shifted but someone was looking over me as it happend when we were awake.
I contacted Garmen concerning the alarm settings. I have my gps set up in miles.
I asked them how to calibrate the miles on the alrarm setting and got a somewhat confused answer. The anchor setting has three digit placement. 0.00. So if this is in miles how do you calibrate?

I sucked in math.

[camaraderie]

Rich... I am assuming you are using statute miles...i.e. land miles...which are 5280ft. so 1.00 miles would be exactly that.
So 0.10 miles would be 528.0 ft and 0.01 miles would be 52.8 feet. Thus you would set your anchor watch for .04 if you wanted about a 200 ft drift circle.
If you are figuring nautical miles then reduce it a bit as they are about 1.2 statute miles. Best...GB

[GordMay]

Nauticalrich:
Sorry, I mis-spoke. I should have said that the anchor could not have REMAINED set - a big difference from NEVER set (sorry).
I''ll stand by my previous comment that a GPS cannot effectively stand an anchor watch, except perhaps on the Bahamma Bank or likewise. You need to give it too much "play" to provide an early alarm.

A Bahammian Moor works well in changing conditions, such as in a tidal flow (or the wind-shift you experienced). This consists of two anchors, set off the bow, at about 160 degrees. It has the added benefit of reducing your swinging room in a crowded anchorage. Of course, you''ve got to estimete the swinging circles of nearby boats, who may be laying otherwise, to anticipate & prevent "conflicts".

OMO
Regards,
Gord

[Jeff_H]

For really aweful conditions, I am getting to be a big fan of the tandem anchor idea. Essentially you put one anchor down with 30 to 40 feet of chain that is shackeled near the end of a chain with a second anchor on it. At worst the second anchor acts a kellet but in the best case acts in tandem to split the loads on the anchors so that they both grab and the apired layout keeps from being able to snatch the first anchor out of the bottom.

Jeff

[nauticalrich]

Thanks to everyone for the replies.
I am now a little better in math.

I am also learning that dead calm at anchor is probably one of the worst conditions for screwing up you anchorage. I saw someone else drag and drift over to my boat a few years ago. It was dead calm.

I''ve also noticed the heavier the wind the harder to get the anchor up. That''s good!

Thanks again.

[Yodagwb]

You could try going to a claw style anchor, they supposedly do best at resetting when you have a switch.