Originally Posted by a64pilot
I gave up on using my Iphone, it seems for whatever reason it's location will travel a couple of miles, for a few seconds and then return. It took an app that showed tracks for me to see what was happening, I have no idea why it does this, but it wakes you up thinking your dragging of course when it does>
It could be the location of the phone
in relation to the positions of the satellites at certain times. I have never noticed any tracking problems on our iPad
, but I don't use it for more than a couple of hours at a time. If you have your phone deep in a hull
, it may not be seeing some of the satellites.
Frankly, I don't see the use of anchor alarms. We are never anchored anywhere that has the freedom of dragging more than a short distance before coming to grief. Right now, for instance, the reef is <100' from our stern. It isn't a matter of how we anchored - anywhere in this small lagoon
would put us 100' from the reef. These are typical types of anchorages for us.
We would need to set the alarm so close as to be up all night with false alerts. Even if we nailed the alarm, if it did go off, we wouldn't have enough time to do anything anyhow.
Instead, we rely on our anchoring and related gear
. We wouldn't be anchored here if we were not 100% positive we would hold (it has been blowing 25kts for 3 days now). When we know there is more marginal holding for us, we don't pick as tight of spots and we simply wake up and check if the weather
goes rough or changes. That is going to happen whether an anchor alarm goes off or not, so the alarm is superfluous.
BTW, we rarely see anyone "drag" anchor. Almost always they are sitting still, then they are off like a shot. Pretty much in these situations, an anchor alarm is not going to alert you in time to avoid trouble unless you have a long distance behind you.