Are There Only Two Anchor Drag Alarm Apps Available for the iPad ?

[ActiveCaptain]

Originally Posted by hellosailor

What kind of position accuracy do you get, with a phone or pad manually set to raw GPS only, all forms of assistance disabled? (That's often a secret menu and not always available to the user.)

Although my iPad is a 3G model (that's the only one with the built-in GPS), I have never enabled a cellular account for it and don't have a SIM for it. The cellular radio is off.

I've made similar tests with the iPhone and cellular off. I don't get much difference although the iPad is always a little better at fix accuracy. Time to first fix is much better on the iPhone with the 3G radio on (seconds vs minutes at times).

iOS devices will use WiFi for ephemeris data too. I've tried turning off WiFi and never noticed a difference. The WiFi radio only seems to effect time to first fix.

Originally Posted by hellosailor

My cell phone is so crude it actually has an antenna. Not much of an antenna, what Chelsea Handler would call a "nubbin". But it does stick up out of the case, and there's no way you would cover it with your hand in any normal way of holding it.

You're right - but few phones have the style any longer. Just for fun, try grabbing it hard with your fingers wrapped around the antenna as best as possible and watch the signal strength over the next 30 seconds.

Antenna design is a black art - I'm sure Apple learned some lessons from this as did all of the other manufacturers. To be really honest, I've never noticed the issue except when demonstrating it purposely. And I'm left-handed - the person most effected because my palm is near the frame break that causes the problem. I think my natural hold is higher up the frame and doesn't cause the issue. The bumper practically ends the problem unless you're trying hard to demonstrate it.

[CaptPaul-]

Great thread. Learning a lot from the tech guys out there. Good to know there here. I've always got tech questions and this was a good place to check this site out.

As always, everything is just an AID to navigation. I've never relied on one AID to get a passage done. By cross referancing gps, charts, DR and bearings I can always get within 10 to 100 feet and I feel really lucky at that.

Not like the old days when I would shoot for Catalina Island from Long Beach and if I didn't see land in 6 hours or so the next stop was Hawaii.

Capt. Paul
s/v Panacea

[hellosailor]

Jeffrey-
"iOS devices will use WiFi for ephemeris data too. "
Well, you may have noticed that no cellular carrier will ever give any customer any more technical data than the address of their billing office. Ergh, Post Box. Wouldn't want the angry villagers to storm the real castle.<G>

"You're right - but few phones have the style any longer. Just for fun, try grabbing it hard with your fingers wrapped around the antenna ..."
One reason why I really try not to DROP the old phone anymore. I'd like a big screen and location-based services and high speed data and wifi, but I find the new phones to be overpriced and, worse, slapdash rushed to market with flaws.
"...Antenna design is a black art " Not really. There ARE books about this stuff, and engineering societies, and microwave communications was around for ages before cell phones. I'm fairly certain that the problem is not the black art, but the accountants shooting down "proper" design and the glamrock whizkids who chant "Pretty pretty Shiny shiny!" and drive the market from both ends.
Maybe what we need is a USN purchasing standard for cell phones, banning all cell phones from military vessels and bases and active duty pesonnel unless they meet certain performance criteria. You know, the same way that a USN standard gave us the 12-volt automotive standard, without passing any "laws" to do it?

[CaptPaul-]

Originally Posted by ActiveCaptain

There are 4 standalone anchor alarm apps for the iPhone. There is also an anchor alarm in iNavX. None of them are anything you'd want to use on even the calmest of nights. They are all pretty bad and all suffer from the requirement to perfectly set them up when you first drop the anchor. Heaven forbid that doesn't go perfectly or you want to change something about your anchor setup.

If you get any of the apps, make sure to try them and experiment a bunch before using them for real.

Navionics does not have an anchor alarm in their app.

Have you used iNavX? I'm tossed between navionics and iNavX. Do you have pros and cons of each?

Thanks..

[ActiveCaptain]

Originally Posted by CaptPaul-

Have you used iNavX? I'm tossed between navionics and iNavX. Do you have pros and cons of each?

Thanks..

I have both including the brand new one released by Navionics last week.

What exactly do you expect to do with it?

[CaptPaul-]

Good chart planning. Back up GPS. Easy to select routes and navigation selections. Easy to place and edit waypoints. And updatable charts. Forward display. I guess I want it all. Lol.

I have the older version of the navionics software and it seems to be a bit limited in the route navigation department so I was searching for someone that had experience with iNavX. Seems to be hyped well.

[sasbibic]

A little different approach for setting and using GPS anchor alarms, if someone is interested, here is link to home page of Personal Anchor Alarm.It uses Java VM so it runs on many different devices.

[mrohr]

I agree that the eyes a great way to see if dragging, but so are the ears (waves start slapping hull at a different angle and rhythm ,so too can the angle of heel and various pitching frequencies alter to alert you to something being amiss. When you spend enough time aboard your craft these changes will even wake you from a sound sleep if you were sober when you turned in.
When you get familiar with your boat you no longer sail it, you wear it!

[ActiveCaptain]

There's nothing that can replace knowing your own boat. But I sure like seeing numeric data to backup what I'm "feeling". I've woken up many times in the middle of the night when wind changes caused different sounds and feelings. In every case, I look and then grab for the objective data. That's the only way I can end up getting back to sleep.