rangefinders and anchoring

Do any of the members use a rangefinder when anchored? Seems it would be useful to check for anchor drag your boat or maybe more importantly someone elses boat dragging down on yours.
Up to 500 + yard seems a good distance. They are available at hunting or golf shops, kind of expensive, about $150.00 and up.

Bushnell® Sport 550 Rangefinder : Cabela's

Radar does this job

Better yet, gps/plotter. Most can be set to beep if boat moves more than a specified amount.

For single handed anchoring I think one may be handy...when I'm out on the bow looking around to see the best drop spot and I want a very accurate quick check of what the difference between 75 feet and 100 of chain might be..I would think a rangefinder handy...but certainly not necessary.

I've used them from a small boat. On water they don't really work past 60 metres / 200 feet. Below that they can be a bit temperamental due to boat motion and lack of hard, flat, reflective targets.

The laser doesn't like broken rocks, seaweed, or barnacles. Any boat motion and it will not lock on and return a distance. Radar/dGPS is far more reliable.

If you boat in an area with a lot of built structures on the beach you might get better results.

Greetings,
Mr. S. I suppose you could bring your clubs and hit a few balls off your aft trunk.

RT Firefly said:

Greetings,
Mr. S. I suppose you could bring your clubs and hit a few balls off your aft trunk.

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Never thought of bouncing balls off the shore or other boats in an anchorage to determine range by club...sounds like fun...

It gives a whole new meaning to "anchor ball"..

I gave up golf about 10 years ago, but maybe one of my sons will have a range finder can borrow next time I go out.

Greetings,
Don't some binoculars have range finders built in? Some sort of scale in the field of view. Barska 7x50 Deep Sea Binoculars | www.kotulas.com | Free Shipping

I have used the chart plotter for determining distance to shore or size of an anchorage. I do this on Navamatics also while choosing anchorages ahead. Would rather do that than arrive and see the "anchorage" you had selected is actually a hole in the wall. Frequently I'll stay on the same scale and move to an anchorage on the plotter that I'm familiar w to get a relative size. If it's just about dark when you get to your chosen anchorage and find it's unsuitable you may have to make do a bit out of the usual envelope of safety. Halving the right anchor for a small anchorage is a big help.

One could practice throwing rocks and keeping a few on board for range finding.

Before I drop the anchor I figure out if my swing will be a factor by eyeball. I drop an anchor watch on my backup laptop running PolarView, but absolutely nothing beats the peace of mind when using the free phone app Drag Queen. Start it up, tell it to set the location, set your alarm distance and leave it running. It used to run the battery down because it uses location services constantly, but something changed because now I run it 10 hours without plugging in the phone. It's probably heresy to admit this, but the past 3 nights we anchored out I never got up to check the laptop... I just looked at my phone and saw we were within 50 feet of the anchor and went back to sleep.

Dave

psneeld said:

Never thought of bouncing balls off the shore or other boats in an anchorage to determine range by club...sounds like fun...

It gives a whole new meaning to "anchor ball"..

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Ha! That was how towboaters found their way around the Fraser River in the fog before Radar became common - a bucket of rocks and a deck hand on the bow.

I think I am in the minority but yes, I have a laser rangefinder at the helm. I try to get range to 2-3 objects - Front, Right, Left and I note it in the daily helm log. This has been very helpful when I have wanted to shutdown the nav systems. It also is a great reference when we go back to the anchorage to get to the same spot approximately.

I have a rangefinder on the boat. I'm not sure why I bought it but I've had it for a long time. I've never thought of using it for anchoring or an anchor drag indication (I have a chart plotter for that) but I have used it to make sure I'm the required distance from a military ship or other restricted place.

If I didn't have it, I don't think I would be in a rush to go out and buy one.

I have one on board and use it to verify my visual guess at distance. It's kind of like hunting practice. I have used it on rare occasions to check distance to other boats and shore since it takes so long for the radar to be ready to use.

Dang. I feel so inadequate. I use a Plastimo iris 50 compass and shoot a couple of bearings. I have some Fujinon binoculars with a compass that I've used as well. Never thought of using a range finder. Cool idea.

Yes. I do have GPS anchor dragging APS and software, but never leave them on overnight.

Drag Queen is not killing your battery because you have not set the alarm!

Xsbank said:

Drag Queen is not killing your battery because you have not set the alarm!

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Yeah. I've got drag queen.

But it still isn't the same as eyeballing a tree out of a port at 3:00 am in the morning.

I use Drag Queen, my plotter and before anchoring if I am near land take a few bearings off my radar.
Cheers
Benn

We usually set a stern anchor , with a small ball, so minor boat movement is easy to spot.

Northern Spy said:

Yeah. I've got drag queen.

But it still isn't the same as eyeballing a tree out of a port at 3:00 am in the morning.

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You're right... it's a lot less scarier than waking up at 3am when the tide changed and the tree's on the other side of the boat!

Dave

Tidahapah said:

I use Drag Queen, my plotter and before anchoring if I am near land take a few bearings off my radar.
Cheers
Benn

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Benn, what distance do you set for the alarm to go off. I was fiddling with the anchor alarm setting on my GPS at New Year, as I had not used it before, (we have never dragged since we got the Sarca), but I thought I should at least know what to do. It defaulted to 0.15 nm - I felt that was too far by far. I knocked it back to 0.01nm I think. What distance do you set, assuming normal anchorage conditions. Ie reasonable swing room, no major obstructions etc..?

Thread creep! ;-)

Would a golf range finder work? Yea, I guess it might, but you would need a laser one. It's not a bad idea.

As for an alarm, I opted for a stand-alone model. ( http://boathooked.com/articles/anchoralarm.html )This, to me, is a great idea. There's no searching thru menus to find the anchor alarm in a chartplotter (and mine is on the flybridge), uses almost no battery power, portable, the cell apps require GPS enabled that will kill your battery (there are easy ways around that I suppose)... I just like the idea of a dedicated box as an alarm. For some reason, I used to always forget to set the alarm at the DROP point, so it was basically a crap shoot.

Still, dragging in the Neuse in any normal weather, is rare. So I am NOT the anchoring expert. That gloppy bottom, once you're set, sticks like glue ;-)

Peter B said:

Benn, what distance do you set for the alarm to go off.

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Since I usually forget to set my anchor location until after I set the anchor, I double the length of my anchor chain and add 50 feet. Not real scientific but works for me. Dave

Peter B said:

Benn, what distance do you set for the alarm to go off. ..................... It defaulted to 0.15 nm - I felt that was too far by far. I knocked it back to 0.01nm I think. What distance do you set, assuming normal anchorage conditions. Ie reasonable swing room, no major obstructions etc..?

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Since you probably measure your rode in feet, nautical miles on an anchor drag alarm would be pretty confusing.

Without doing a lot of calculations, 100' of rode would allow a swing of about 200'. So, with 100' of rode, I set the alarm to 250 feet or so. If it wakes me up during the night and I determine we're not dragging, I just add a few more feet and go back to bed.

Never used a laser range finder before, but if in the middle of the night the current swapped 180* wouldnt it take a while to determine if you were holding or not? With a chartplotter and a waypoint where the anchor was dropped, you can determine if you are still in the swing radius of the WPT in a couple seconds. You're either in the circle or you are not.
I think the RF would be good for checking distance to other boats. Especially ones drifting down on you.

>but if in the middle of the night the current swapped 180* wouldnt it take a while to determine if you were holding or not?<

NOPE , a glance at how the stern set anchor was holding would do.

WE use a Bahama more set almost 100% of the time as it takes less time to set than program some electric gadget.

The gadget will tell me after we are drifting out of the bay , the stern anchor PREVENTS the problem.

In my experience the "gadget" takes only seconds to set and it wakes me if the boat leaves the circle I've set.

A stern anchor in an area with reversing tidal current will put the current against the stern at some point. I've been taught that the pointy end of the boat should face the current for the least resistance.

A stern anchor would take more time and effort to set and there's no windlass at the stern.

I set the tracking on the Nobeltec. Gives a visual representation if we are doing tide swing (normal) or something more(dragging). A longish tail outside of swing circle will alert watchstander.

I've used radar a few times to get accurate distance info for other boats. It works pretty well but seems to be a big effort. Also, turning on your radar when another boat is coming into an anchorage (when you have an open array) seems a little unfriendly to me.

I'd love to know which laser rangefinders are being used and which ones work well - 1,000 feet would be a good maximum distance if that's even possible with the technology.