Avoiding Debris

[H28]

What about forward looking sonar?


At 30 mph? 44 feet per second......what is the effective range of forward looking sonar?

 

[FlyMeAway]

What about forward looking sonar?


At 30 mph? 44 feet per second......what is the effective range of forward looking sonar?

The effective range of downward-looking sonar is several thousand feet, in some cases up to 10,000 ft... Range is not the issue, it would be perfectly feasible. The issues are:
1) Interference (viz. if everybody had 10,000 foot sonar pinging all the time vertically rather than in an narrow scope below the boat, it could be... problematic)
2) Effects on marine life (not sure about this one, but there are big issues with sonar and whales)

 

[H28]

the original post was 30mph and debris, presumably in front of the boat...by the time it is under the boat, too late

How does downward looking sonar help me avoid a debris in front of me?

and even if it did, at 18knots I lose depth sounding on Lake Michigan.......

 

[FlyMeAway]

the original post was 30mph and debris, presumably in front of the boat...by the time it is under the boat, too late

How does downward looking sonar help me avoid a debris in front of me?

and even if it did, at 18knots I lose depth sounding on Lake Michigan.......

The point was about range. If downward-looking sonar thousands of feet of range, then downward-looking sonar would too. The question was about sonar range.

You lose sonar at speed because of bubbles beneath the hull of the boat, not because of transmission speed. This can be engineered for. Sound travels at about 1,400m/sec through water, the speed of your boat doesn't really matter.

 

[HookedUp]

Around here in the Chesapeake Bay we have lots of crab pots and pound nets in addition to the occasional wood dislodged from a dock or other debris. I've found radar is invaluable at night and in fog. However, it can't see everything.

After one too many moonless/starless nights I added a night vision camera to view on my iPad. It will view nighttime in color if there is any light source, but on those really dark nights I switch to black/white and it still picks up what I need to see. I mount the camera forward and get a good view of the water and what's on it. I still travel at slower speeds than daytime, but having the camera sure makes the night navigation much more relaxed.

I haven't used it in fog yet, so I can't say how it would perform. I have relied on my radar in fog before, but I really slow down when there is fog. More than once I've been surprised by things in the fog. It really changes your perspective when the fog is thick.

 

[H28]

The point was about range. If downward-looking sonar thousands of feet of range, then downward-looking sonar would too. The question was about sonar range.

please re-read the question that was asked a 3:49: What about forward looking sonar?

my comment at 4:24; What is the effective range of forward looking sonar?

I am still struggling to see why the point about downward looking sonar was introduced or is relevant.

back to the 3:49 question: "what about forward looking sonar?"

Having spent time "googling" it, and not being an expert, there seems to be a wide range of capabilities re the effective forward range (per the question asked) but none of these systems are designed to pick out debris ahead of the boat. So, absent Myth Busters doing a test: I'd say thumbs down on the efficacy of using your sonar to avoid debris and return to my first post: "a sharp lookout is your best defense" relative to the original post: "if anyone has any tips for watching for debris ............"