sahockey
Veteran Member
Hi forum,
I responded to a thread about a Garmin anchor alarm asking opinions on this idea. In hindsite it is probably more appropriate to start my own thread. Please read this and comment on any shortcomings to this concept. I’ve enjoyed the reasoned and knowledgeable responses from members of this group and look forward you critiques.
Most anchor alarms depend on a large circle with the radius being the length of your anchor chain deployed. This is necessary because of swinging at anchor which could even involve up to a 180 degree wind or current shift. Of course the problem with this is two fold. 1. The center of the circle is difficult to mark while anchoring. 2. The length of rode let out is affected by how tight it is to the anchor. If either of these aren’t accurately marked there will potentially be a large error possibility causing false alarms or even worse no alarm in time. In today’s crowded anchorages this is a serious shortcoming.
The concept I’m advocating does not track the boat through its swings. It only tracks the anchor. Thus the boat could move 400’ (with a scope of 200’ out) and the alarm would not sound unless the anchor moved 5’ to 10’ or any longer amount you decided was safe.
Get a gps locator that is powered by a battery in a waterproof design. There are many small variations of this used for tracking wayward dogs. You would want to get one that does not require a monthly fee. They come with software that allows you to set it up most anyway you desire. Attach this locator to a float that would keep it above the water. Tie that float with a rope to the trip location on your anchor with a device in between which keeps the float directly or almost directly over your anchor. This device could be an adjustable shock cord or even a more complicated device that maintains tension on the attachment rope to adjust for tides and currents to keep the float above your anchor. Thus the center of your circle is marked and the alarm is independent of the amount of rode you have out. An additional benefit of this method is if your anchor gets snagged you have a trip rope you can use to get it free. What do you think?
I responded to a thread about a Garmin anchor alarm asking opinions on this idea. In hindsite it is probably more appropriate to start my own thread. Please read this and comment on any shortcomings to this concept. I’ve enjoyed the reasoned and knowledgeable responses from members of this group and look forward you critiques.
Most anchor alarms depend on a large circle with the radius being the length of your anchor chain deployed. This is necessary because of swinging at anchor which could even involve up to a 180 degree wind or current shift. Of course the problem with this is two fold. 1. The center of the circle is difficult to mark while anchoring. 2. The length of rode let out is affected by how tight it is to the anchor. If either of these aren’t accurately marked there will potentially be a large error possibility causing false alarms or even worse no alarm in time. In today’s crowded anchorages this is a serious shortcoming.
The concept I’m advocating does not track the boat through its swings. It only tracks the anchor. Thus the boat could move 400’ (with a scope of 200’ out) and the alarm would not sound unless the anchor moved 5’ to 10’ or any longer amount you decided was safe.
Get a gps locator that is powered by a battery in a waterproof design. There are many small variations of this used for tracking wayward dogs. You would want to get one that does not require a monthly fee. They come with software that allows you to set it up most anyway you desire. Attach this locator to a float that would keep it above the water. Tie that float with a rope to the trip location on your anchor with a device in between which keeps the float directly or almost directly over your anchor. This device could be an adjustable shock cord or even a more complicated device that maintains tension on the attachment rope to adjust for tides and currents to keep the float above your anchor. Thus the center of your circle is marked and the alarm is independent of the amount of rode you have out. An additional benefit of this method is if your anchor gets snagged you have a trip rope you can use to get it free. What do you think?