Avoiding flotsam and marine animals

[jsc7]

One of the dangers of boating is flotsam such as logs or marine animals, such as whales. In the movie "All is Lost" the sailboat gets into trouble because it gets holed by a drifting container at night. The corner of the steel container just goes right through the hull of the boat.

During the daytime, the watch can book for V-ripples, but anything low in the water can be difficult to see.

Are there any creative approaches to avoiding flotsam and other floating obstacles? What about thermal imaging monoculars? Would they be able to more easily spot debris in the water?

[sv Grateful]

Inshore, where most of the junk is, you just have to keep a sharp lookout.

Offshore? It won't take long for you to realize that the ocean is BIG and there is not much in it. As far as I am concerned you just sail, look out for traffic and accept the truly minuscule chance of running into something as a risk of the game. There are much bigger threats (think fire, fresh water contamination, cutting yourself fixing dinner) that eclipse the danger of "running into something."

[Taichungman]

"All is Lost" ..That was one stupid show. Even if you keep a good lookout at all times, you probably won't see anything until you hit it. Just by luck I saw a log floating a day out of Panama on the way to the Galápagos and we were able to avoid it. But, last year we ran over a good size tree limb (not trunk) in the Chesapeake Bay but no damage. Back in the 80's, I saw a huge white object floating in the Gulf of Mex. I decided to investigate and found a rectangle piece of styrofoam bigger than my boat, the top was a least 6' from the waterline. It's probably still out there somewhere.

There is not much you can do but keep a good lookout and maybe you'll see the really big things that might be a problem, like container ships and Navy destroyers.

[Zven]

There is forward-looking sonar, but I understand it's only currently useful at very low speeds.
Probably this will improve over time, though.
I'd imagine, with those devices it should be possible to set an alarm to go off if one is about to hit a massive underwater object - be it reef, whale, log or container.