Laser Range Finder for Dock Distances


#1

Anyone use handheld laser rangefinders made for industrial or sport-hunting use to figure out distances when landing or leaving the dock? Where I work our boats are always landing and departing from congested docks, quite often in strong winds. The captain will have ABs on the bow and stern radioing him distances from other boats and the dock, to avoid allision. Because ABs are rarely accurate at judging distances, the captain usually takes the distance with a grain of salt. As one captain put it, “I’m not listening to the distance they’re telling me. I’m listening to the amount of panic in their voice”. Seems to me there must be a tech solution to the problem these days.


#2

Range finders will end up lost or broken. Teach your ABs to gauge distances. It’s not that hard.


#3

The ship I was on before this one had the mates on both the bow and stern use range finders every time when docking. The Capt. keeps one by his chair all the time too.
This ship almost always anchors out, so not needed so much.


#4

Estimate range by bollard distances. Even the worst AB can count how many bollards between you and the vessel ahead or astern. Other than that, my rule of thumb while calling distances to the captain was always to go with a worst case estimate. If it looks like 50 meters, it’s 40 meters. Never used a range finder but know some that did.


#5

Not much when docking, but I’ve found it pretty useful working around rigs/platforms.


#6

[QUOTE=freighterman;193041]Anyone use handheld laser rangefinders made for industrial or sport-hunting use to figure out distances when landing or leaving the dock? Where I work our boats are always landing and departing from congested docks, quite often in strong winds. The captain will have ABs on the bow and stern radioing him distances from other boats and the dock, to avoid allision. Because ABs are rarely accurate at judging distances, the captain usually takes the distance with a grain of salt. As one captain put it, “I’m not listening to the distance they’re telling me. I’m listening to the amount of panic in their voice”. Seems to me there must be a tech solution to the problem these days.[/QUOTE]

I know one captain that tried using one, he was unhappy with the inaccurate distances and maybe not capable of using the “voice panic gauge”. I don’t think he ended up using it much.

There are a couple different situations, one is the parallel parking situation which is simple and the bollard counting method works.

In the case of coming off the dock and having to turn 180 degrees in a tight spot it’s a little more difficult. In that case getting a distance off from a person on the bow is not as useful. A distance from the bridge would be more useful to gauge if the swing was clear or not.


#7

So the laser rangefinder was verified to be inaccurate? Just curious.


#8

[QUOTE=Slick Cam;193103]So the laser rangefinder was verified to be inaccurate? Just curious.[/QUOTE]

No, my post was poorly worded, one captain was unhappy with the inaccurate distance reports he was getting and tried using a rangefinder.

Had a new third mate one time, reports “one hundred feet to the ship astern”. I told him to report distances in meters. He says “Ok captain, one hundred meters to the ship astern”


#9

I’ve toyed with the idea of using laser range finders off and on over the years and never bit the bullet. Rather, I lay out on the chart visual references I might use and note the distance to the object of concern ( example: when buoy 2 and Acme tanker pier line up I should have 500 feet to the dock).

When listening to crew calling off distances I am listening for not just the distance off but the rate of closure, if any. Nobody can expect accurate distances over 200’ but they can tell if the available space is increasing and decreasing. It’s like an old captain I sailed with used to say: “every bodies 100 feet is different, their zero is pretty much the same.”


#10

Our Second Mate brought a laser range finder, used in archery, cost about $340. Magnified monocular has cross hairs so you know what you are targeting for a distance. Reads yards or meters, he tells me the device also has a tilt meter to help determine horizontal distance from actual line of site distance, ex, when on a high deck looking down at a low pier, the unit can determine the angle you are looking down at, and use that to extract the horizontal distance from the longer line of site.
But like most, we already have too many gadgets and gizmos, and too much to train crew on, to be excited about requisitioning additional equipment, that I would have to train the new Mate how to use, etc.
I usually tell Mate’s, when standing on one corner of the stern, that the opposite corner of the stern is about 50’ away, so they should use that as a gauge. Our visibility is terrible from the Bridge, and with the Bridge Fwd, the stern feedback is necessary, but not always accurate.


#11

one of our mates uses his hunting rangefinder on occasion. I’m not sure of the model, but it seems to work pretty well out to 500yds. His distances have become a lot more accurate, which comes in handy when trying to get into king cove in the dark with the current rippin out of the lagoon. Not all guys will need it, but I would think it’s a handy tool to have, especially for some of the places Coastal goes into.


#12

I always tell guys to imagine a 40’ container something relative in size to judge a distance, seems to help some.


#13

gps on bow and stern and a good charts and a giant ecdis screen is how cruise ships do it


#14

Laser range finders might be good if all your deck crew each get one eye of their eyes gouged out by a massive octopus in heat, and they can no longer judge distances.


#15

[QUOTE=lm1883;193123]When listening to crew calling off distances I am listening for not just the distance off but the rate of closure, if any. Nobody can expect accurate distances over 200’ but they can tell if the available space is increasing and decreasing. It’s like an old captain I sailed with used to say: “every bodies 100 feet is different, their zero is pretty much the same.”[/QUOTE]

Exactly this. Rarely do I need to know an exact distance, I’m more concerned with rate of closure. The only times I’ve ever cared for precise calls were backing into C-Port 1 but then the distance was in inches anyway…


#16

ECDIS is on the majority of international vessels these days and is a great tool. When spinning in a basin, close to structure, buoys, or shallows and getting distances from the crew it is great to be able to look at the screen and get a warm fuzzy, but sometimes, it doesn’t work that way. On occasion (not often, but often enough) the vessels ECDIS silhouette does not fully match its real life one, and can be off by as much as a boat length. To insure its accuracy frequently verify the vessels ECDIS “footprint” along side the pier and while under way in channels. Also, if using a “predictor” verify the speed inputs that go into the unit. If the calculation for the speed is to long it might make the “Predictor” less accurate.

See below


#17

In regards to the specifics of one operation in which accurate distance estimation can be helpful. Other operations in other trades will be widely different:

In terms of landing a boat at a dock: Imagine a U-shaped basin of docks. Imagine each side of the “U” is two boats longs. Maybe 600 feet on a side. Imagine near one of the corners of the “U”, where a side meets the “bottom”, there is a berth open. Maybe one boat-length long plus 10 feet. The skipper has to land his boat in that berth, with a vessel moored ahead and astern, with five feet to spare from each boat. Skipper probably has a single thruster. But maybe not. Maybe twin screw. Maybe single screw. Never a tug. If it’s one of our house forward boats, the skipper can’t see the stern from the wheelhouse because of the raised poop. Imagine the wind at 40 knots, setting the boat down into the basin, and it’s driving rain. Imagine plenty of boats milling about the basin, and it’s the middle of the night. The skipper has himself, one mate, maybe a couple of trusted ABs to shoehorn the 260’ boat in the 270’ slot. A few other hands to handle lines, but no one else to rely on to conn the boat in.

That’s a fair description of the environment our boats land and depart in, and the context in which I was inquiring about rangefinders Not the worst conditions, but fairly challenging. Throw in Dutch Harbor williwaws, where storm force winds can completely reverse directions within a matter of minutes and close-quarters boat handling can become difficult. A near sighted AB, simultaneously talking on the handheld and fast-coiling his heaving line before it gets sucked in the wheels, after missing the dock, in pouring rain, can be excused not getting distances exact, when the relative positions of docks and boats, both fixed and moving, are changing fast. But after an internet search I can’t find any technology that would help in this case. There is a saying we have “Dutch Harbor is where technology goes to die”. All the electronic devices which seem so rugged elsewhere usually expire after a day or two of Aleutian winter.


#18

[QUOTE=freighterman;193704]In regards to the specifics of one operation in which accurate distance estimation can be helpful. Other operations in other trades will be widely different:

In terms of landing a boat at a dock: Imagine a U-shaped basin of docks. Imagine each side of the “U” is two boats longs. Maybe 600 feet on a side. Imagine near one of the corners of the “U”, where a side meets the “bottom”, there is a berth open. Maybe one boat-length long plus 10 feet. The skipper has to land his boat in that berth, with a vessel moored ahead and astern, with five feet to spare from each boat. Skipper probably has a single thruster. But maybe not. Maybe twin screw. Maybe single screw. Never a tug. If it’s one of our house forward boats, the skipper can’t see the stern from the wheelhouse because of the raised poop. Imagine the wind at 40 knots, setting the boat down into the basin, and it’s driving rain. Imagine plenty of boats milling about the basin, and it’s the middle of the night. The skipper has himself, one mate, maybe a couple of trusted ABs to shoehorn the 260’ boat in the 270’ slot. A few other hands to handle lines, but no one else to rely on to conn the boat in.

That’s a fair description of the environment our boats land and depart in, and the context in which I was inquiring about rangefinders Not the worst conditions, but fairly challenging. Throw in Dutch Harbor williwaws, where storm force winds can completely reverse directions within a matter of minutes and close-quarters boat handling can become difficult. A near sighted AB, simultaneously talking on the handheld and fast-coiling his heaving line before it gets sucked in the wheels, after missing the dock, in pouring rain, can be excused not getting distances exact, when the relative positions of docks and boats, both fixed and moving, are changing fast. But after an internet search I can’t find any technology that would help in this case. There is a saying we have “Dutch Harbor is where technology goes to die”. All the electronic devices which seem so rugged elsewhere usually expire after a day or two of Aleutian winter.[/QUOTE]

I use refrigerators. I’ll sit the crew down and tell them to imagine a line of refrigerators laid end to end. 4 fridge, 5 fridge, 2 fridges. It’s alot easier for someone to visualize than just distances, and I find when you really need it you want to know distances under 30 feet or so. It’s easy to muff 10 or 20 feet but it’s a lot harder to think you could fit 4 fridges in there when you can only fit two. Anything that helps them project an actual distance onto the water.


#19

Freighterman google RangeGuard manufactured by Guidance Navigation. There are a few videos of the sea trials for it on the internet. We did the Gulf Of Mexico trials and it was a nice useful piece of equipment. Exactly what you’re looking for.


#20

Cool. I like to use Birkin Bags to measure distances. 4 Birkin Bags, 5 Birkin Bags, 2 Birkin Bags. My ABs find it a lot easier to eye ball using this method over any other.