Hazard Detection System

[JD Ray]

In preparing to install my new Garmin chartplotter, which came with a transducer, I looked into what other things that could be connected to it. One of the options is a forward-looking sonar (the transducer alone is $1500, so certainly something for a later date, if at all). I was momentarily excited by the idea, because the PNW waters are rife with floating hazards, particularly driftwood. But the manual says it provides a forward look at angles between 20 degrees and 90 degrees. The 90-degree part pairs nicely with the standard downward-looking, aft-mounted transducer, but a big gap exists in the 0-20 degree forward-looking range (that's 20 degrees if you are looking at the boat from the side), right where logs and other flotsam lurks.

What technologies, if any, help spot material in the water in that 0-20 degree gap? Sure, your eyes will be your best tools, but there's a lot of junk floating out there just sub-surface, and it seems like having a bit of a crutch might be really useful.

 

[Larry M]

How fast do you travel? At 6-8 knots most floaters will just bounce off the hull. Your eyes are the best for surface stuff.

 

[Sababa]

Certain FLIR thermal cameras are supposed to offer floating object detection with the Clearcruise augmented reality feature of Raymarine MFDs. Don’t know if anything similar is available for Garmin.

https://www.flir.com/products/m232/?vertical=maritime&segment=solutions

 

[JD Ray]

How fast do you travel? At 6-8 knots most floaters will just bounce off the hull. Your eyes are the best for surface stuff.

Slow boating for sure. This is more of an academic exercise than anything. That said, the current boat (once it's in the water; hopefully in the next two weeks) should top out upward of 40 mph (not a trawler). But like the guy at the boatyard said, "You know what we call people who go over ten knots around here? Customers. Too much wood in the water for speeds like that."

 

[Larry M]

I like the "customers".

Seriously, we spent 12 plus years in the PNW and an equal number of years in the warm water (shallow water for the most part). I never met a boater who said one saved them from an impact. They sound great but I think they're over hyped on what they can do for the average boater. Just saying.

 

[JD Ray]

Wow, what a rabbit hole.

It appears that there are systems out there, primarily aimed at sailboats. In the case of this one, the OSCAR, the lowest-priced one (around $10K) has a minimum mount height of 8 m (~25'), so not practical for Loop-ready MVs. They have a MV-targeted system, but it's much more complicated and appears to be super-yacht-ish ("price on request"). Interesting stuff, though.

 

[Mac2]

Timely post. I'm planning on the Garmin as well and I'm going to get the forward looking sonar along with the clearvu transducer. My idea was to use these systems for entering remote anchorages. The sonar for the uncharted rock and the clearvu for avoiding dropping my anchor on old logging gear (cables etc.). I've mentioned in previous posts about my recent trip to the San Juans and seeing more logs then ever and I was in thick fog the majority of the trip there. The logs I saw were the type that would not "bounce" off.

I'm thinking the floating log/debris might best be seen by a radar set for close range. I remember seeing an advertisement about a digital radar claiming to be able to see floating logs. Anyone have an opinion on this?

 

[DDW]

I can see big high floating logs on digital radar, provided the sea is flat. With even little wind waves, they are lost in the noise. The most dangerous flotsam is a deadhead, floating upright with nothing showing above the surface and weighing many tons. A steel boat might bounce off of that but your eyes are likely the only thing with a possibility of detection, and again in a seaway they won't.

 

[Mac2]

I can see big high floating logs on digital radar, provided the sea is flat. With even little wind waves, they are lost in the noise. The most dangerous flotsam is a deadhead, floating upright with nothing showing above the surface and weighing many tons. A steel boat might bounce off of that but your eyes are likely the only thing with a possibility of detection, and again in a seaway they won't.

Bummer! When I get the forward looking sonar, I'll do some testing on deadheads (the monsters) to see if they can be "seen" and if so, how close to the surface and how far out. Maybe even experiment with speeds to verify sensitivity of the transducer. I'm guessing the results won't be that great, or it would be in the sales brochure.

 

[syjos]

I have a Hazard Detection System on Sandpiper with a loud alarm.

Its called a Wife

 

[sjisailor]

Don't know about the systems but would be skeptical. The one time we had prop damage from a deadhead, the systems would not have helped. We got in a mass of submerged, barely and only occasionally visible logs in the Swinomish Channel south of La Conner (PNW town on a channel, for others). We were doing only 5 knots and threading carefully among them. Then heard a loud bump and prop started sounding funny. Never saw it.

Luckily prop got us back and shaft alignment was OK, just had to fix the prop blades. (Also ordered a spare prop for next time, as they had a 5 month wait.

 

[jungpeter]

I have a Hazard Detection System on Sandpiper with a loud alarm.

Its called a Wife

Ditto that. There's no substitute for multiple MK-1 eyeballs. And even with excellent watch keeping, the likelihood of contact with a damaging (floating or submerged) object in the PNW is 100%. Some will hurt, some will not.

We're all members of the Mother Earth Society. Some of us have met Mother Earth, all of us will.

To JD Ray-save your money you'll likely spend on your electronic "crutch", and sock it away for that inevitable day in the future when that dreaded "thump, thump, BANG" occurs. And rest easy-it happens to all of us eventually. Part of the cost of operation here in the PNW.

Regards,

Pete

 

[twistedtree]

Such a system is the holy grail of boating.

As DDW pointed out radar and other “vision” systems can help in some cases, but only in calm water. And any surface chop, let alone waves, and these systems will not help at all. I’ve personally tried many different brands and models of radar, plus a couple of different FLIR cameras.

Forward sonars are also limited. If you look horizontally as you would want to see surface debris, you get overwhelmed by surface clutter.

 

[Mac2]

Great comments! Very helpful. Hope I'm not hijacking this thread. Now my thought process shifts to my eyeballs being a priority. In the fog I can slow down to a avoidance speed, or speed that minimizes damage. Now, for nighttime running (other then not doing it), what recommendations do you have for an led array that works for seeing ahead, but isn't ridiculous for eating up amps? Do you use a light for far and one for close? I'm not talking about a spot light, but something that is practical for continuous use, or is this not practical without running a generator the whole time?

 

[Sababa]

I have a powerful Rigid M-Series light bar on top of my pilot house. It’s good for picking out markers, shore features, and other boats, but the water just swallows it up. I can’t imagine how much brighter it would have to be to see something like a deadhead in the water on a dark night.

 

[ssobol]

I have a powerful Rigid M-Series light bar on top of my pilot house. It’s good for picking out markers, shore features, and other boats, but the water just swallows it up. I can’t imagine how much brighter it would have to be to see something like a deadhead in the water on a dark night.

Water usually reflects the light off into the distance and doesn't bounce it back (angle of incidence and all that). A floating deadhead is more likely to be visible if it is floating high enough. Unfortunately, lots of them don't, hence the term.

 

[JD Ray]

What’s a reasonable distance away to see something and still be able to avoid it (presuming it’s not moving and presuming it’s a normal-sized hazard and not an iceberg or something)?

 

[Mac2]

What’s a reasonable distance away to see something and still be able to avoid it (presuming it’s not moving and presuming it’s a normal-sized hazard and not an iceberg or something)?

Every boat will be different. I'm thinking a plan of what to do is more important. I learned that my auto pilot is to slow for the "emergency dodge" function compared to me putting the auto in standby and hand steering.

Also, if I can't dodge in time, where do I want to take the hit. I would take it straight on if I couldn't completely dodge the item and hope the stem/keel and protected props save me (slowing as much as possible).

I was headed back to the dock at night and I was on Lake Union when a corked fishing net showed up about 50 feet in front of my boat. I later learned local tribes are allowed to do this (fish for sockeye) on occasion.

No way I could stop, or dodge. I put the boat (Krogen Manatee) in neutral and the net slipped under my full keel and protected prop. with no issues. I later learned if I had snagged the net I would have paid for a new net and all the fish the net owner would have caught all season-which I'm sure would have been record amounts.

 

[twistedtree]

I think the issue with any sort of headlight system is that it almost certainly violates COLREGS. We all know you need to display appropriate nav lights at night. But you are also prohibited from having additional lighting that can obscure or confuse your nav lights. Ok, now everyone can go off on why the rules are stupid, if no other boat is around, if I have a huge light everyone will see me anyway, etc. etc. Ready, set, go!

 

[Mac2]

I think the issue with any sort of headlight system is that it almost certainly violates COLREGS. We all know you need to display appropriate nav lights at night. But you are also prohibited from having additional lighting that can obscure or confuse your nav lights. Ok, now everyone can go off on why the rules are stupid, if no other boat is around, if I have a huge light everyone will see me anyway, etc. etc. Ready, set, go!

Something I had not considered, so thanks.

 

[rslifkin]

I think the issue with any sort of headlight system is that it almost certainly violates COLREGS. We all know you need to display appropriate nav lights at night. But you are also prohibited from having additional lighting that can obscure or confuse your nav lights. Ok, now everyone can go off on why the rules are stupid, if no other boat is around, if I have a huge light everyone will see me anyway, etc. etc. Ready, set, go!

Good point. Although logically, if you're using any lighting bright enough to do that (beyond brief use of a spotlight), you're probably somewhere that nobody is around to see your nav lights anyway (otherwise you'd be blinding everyone else). So I wouldn't necessarily say not to have them, but definitely be careful about when you use them to avoid blinding or confusing other boats.

It's like high beams on a car. Doesn't really matter if you pile a bunch of extra not-road-legal driving lights on for use with the high beams. It's technically illegal, but nobody will bother you in most places because nobody else should ever see them on (they'd only be used on empty roads).

 

[twistedtree]

I came dangerously close to a collision because of just such an over-lighting situation. I mistook a fishing boat with bright forward deck lights for a stationary shore facility. It was just a bunch of giant white lighting with no nav lights distinguishable in any way, and appeared to remain stationary along the shore line. The result was a dangerous avoidance situation by the time I realized it was a moving (and closing on me) boat and not stationary shore lighting.


Even on cruise ships, you will find that despite all their non-nav lighting at night, it's such that the nav lights are still clearly distinguishable.


There is a reason why boats don't have headlights.

 

[Sababa]

The full Dashew: https://setsail.com/optimizing-for-night-vision/

 

[Portage_Bay]

I came dangerously close to a collision because of just such an over-lighting situation. I mistook a fishing boat with bright forward deck lights for a stationary shore facility. It was just a bunch of giant white lighting with no nav lights distinguishable in any way, and appeared to remain stationary along the shore line. The result was a dangerous avoidance situation by the time I realized it was a moving (and closing on me) boat and not stationary shore lighting.


Even on cruise ships, you will find that despite all their non-nav lighting at night, it's such that the nav lights are still clearly distinguishable.


There is a reason why boats don't have headlights.

Fishing boats with extremely bright lighting are very common around here, west coast of North America. Some so bright they are blinding. Add to the problem the capt is not keeping a proper watch paying more attention to his nets/gear and deck crew than what's out in front of him. Probably why he didn't do anything to avoid or warn you. To help me sort things out I always run with radar at night. AIS is a big help but some fish boats turn it off when fishing.

 

[Portage_Bay]

No way I could stop, or dodge. I put the boat (Krogen Manatee) in neutral and the net slipped under my full keel and protected prop. with no issues. I later learned if I had snagged the net I would have paid for a new net and all the fish the net owner would have caught all season-which I'm sure would have been record amounts.

Yes, once you hit the point of no return neutral is the only defense.

Being required to buy the fisherman a new net and replacing lost catch is a new one for me, been threading my way around gill nest for decades. Had to cut myself free one time. Nothing came of it. Curious where you learned that? Source if possible please? Searching turns up nothing.

 

[CharlieO.]

Fishing boats with extremely bright lighting are very common around here, west coast of North America. Some so bright they are blinding. Add to the problem the capt is not keeping a proper watch paying more attention to his nets/gear and deck crew than what's out in front of him. Probably why he didn't do anything to avoid or warn you. To help me sort things out I always run with radar at night. AIS is a big help but some fish boats turn it off when fishing.

Most fishing boats only have their crab lights and/or deck lights on when actively fishing, once steaming they are generally off.

 

[Portage_Bay]

Most fishing boats only have their crab lights and/or deck lights on when actively fishing, once steaming they are generally off.

Not so much around here. They seem to turn on the bright lights a soon as they light off the engines and leave them on until they return to the dock. I've had to follow fishing boat into rivers and harbors with deck lights so bright I could not see anything. The only defense was to stop and let them go on.

 

[CharlieO.]

I guess we would when coming into harbor at night, but at sea they were generally off unless we were working. Gulf of Alaska/ Prince William Sound/ Bristol Bay/ Aleutians. I'm not really familiar with working boats on the upper west coast.

 

[Shrew]

At 8 knots you're travelling 13.5 ft/second. If your forward looking sonar looks out 40 feet in front of the boat you have 2.96 seconds to see it in the display and take action before a collision.

In the time it takes to scan the gauges, scan the horizon and then scan the displays, you will miss it.

 

[ssobol]

At 8 knots you're travelling 13.5 ft/second. If your forward looking sonar looks out 40 feet in front of the boat you have 2.96 seconds to see it in the display and take action before a collision.

In the time it takes to scan the gauges, scan the horizon and then scan the displays, you will miss it.

The 2.96 seconds also does not account for the response time of your vessel to a sudden command input.