Will a laser pointer work for pointing at whitewater?

Question

I have been doing whitewater kayaking for some time now, and still have a great deal to learn. For difficult places, it is normal for me to stand outside and talk about which lines are good and which places to avoid. More experienced people can simply point out salient features to each other, "Go right after you have boofed over that ridge, with enough time to steer clear of the undercut rock". I am still at the stage where I have to learn how to recognize a barely visible ridge, to know where I will need to boof, to spot which one of the dozens of rocks is undercut.

As pointing with a finger only gets us so far, I thought of using a laser pointer. I even found a model which is waterproof (meant for divers). But I am reluctant to try it, as it is expensive enough to hurt if it turns out to be useless.

• if I get a laser pointer, will I be able to see the dot on the water surface?
• assuming that it works, what would be the minimal strength required to see the dot in direct sunlight?
• Again assuming that it works, which colors will work? I was surprised to read some diver mentioning that underwater, green is better than red, but have no idea if this will hold for the surface.
• The water surface reflects more like a mirror than like a random solid surface - will this be as damaging for the eyesight as having the pointer itself pointed directly at the eyes? Yes, the water is probably somewhat foamy, but it tends to have still places too.
• are there other potential problems with my idea?
• are there easier solutions to the same problem?

Update I am specifically asking about good methods for pointing, not for finding the line in other ways. I am more concerned with learning to read the water than with finding the perfect line. To those who don't know what it looks like, the following picture is a good example. The important thing in the picture are not the stones, but the shape and behavior of the water in the different (small) places between them.

Answer 1

Laser Pointers

I've spent years in whitewater and can somewhat appreciate your struggle with pointing and vague references to features. I've played with inexpensive laser pointers at night in camps next to whitewater. From what I've seen they wouldn't really work at all in the day time.

As far as other suggestions there are a few ways to handle beta.

Better Pointing

One method for better pointing is getting next to a the feature of note. Often I've had more novice paddlers catch an eddy close to a feature so point with my hand is not ambiguous. This allows me to talk about specifics a feature. I've done this to show new paddlers what undercuts, sieves, curling waves, eddy lines, holes, splat rocks etc etc etc look like. Likewise, simple hand signals like a paddle up when moving past a feature of note can be helpful.

I would caution though, standard whitewater protocol is to "point-to-positive". In other words when we can't communicate clearly I will point where you should be and NEVER point at hazardous features. When you can have a conversation obviously it's a little different.

Better descriptions

The key to good beta is know how much to give. I'm a big fan of short and sweet with a little bit of color if needed.

Start Right Move left.

Enter Left and drive right to miss an undercut.

Down the middle. Keep your bow up on the boofs.

When you are in the rapid this stuff is a lot easier to remember and will generally result in better lines. If the simple beta isn't enough beta then you probably should take a step back in difficulty. Likewise for many scouts. If you can't see the lines yourself you should probably take a step back, unless you are looking at CL III water as a new boater.

Blue Angel Boating

Another method to fix the problem of beta is to provide brief descriptions but run rapids in a close group one after another. It's one thing to say there is a ridge to boof but it's difficult to identify from shore. It's another to be 6 feet behind the boater who knows where they are going and following their exact line. This is one of the best methods for quickly descending rivers as it does not require a bank scout. Obviously it has it's drawbacks in lack of shore safety and if the guide blows the line both of you might be in trouble. I think the fact that the boats are tightly grouped improves safety as in boats rescues are fast effective, and in many cases much safer for the rescuer.

EDIT: I've added a little bit on better pointing.

Answer 2

An alternative you might want to consider is taking a model/diorama making kit.

This is a technique widely used by the military, especially for infantry and SF platoon and section commanders. Although it is a bit of extra faff it makes explaining complex plans on real geography much much easier and is definitely worth the effort.

The simplest method is just using improvised materials but a small kit can make the job much easier. In this particular case I would suggest.

• A lightweight blue scarf to represent the river.
• Use found pebbles to represent rocks etc
• a set of laminated numbers and letters (like scrabble tiles) to indicate specific reference points you could also make up other symbols for specific hazards or blank tiles to mark as you need
• coloured string to indicate routes or other linear features

If you want to get really fancy you could use cotton wool or sprinkle powdered milk or talc to indicate white water.

A decent model kt can fit in a large tobacco tin and allows you to create a usable model in minutes.

Answer 3

You might just get away with highlighting white water itself and rocks. Clear water wouldn't reflect the light in the right direction. But you'd need a very bright, possibly illegal and/or dangerous laser pointer.

My waterproof video camera has a 1mW approx red laser as an aiming guide. Even in a river valley on a dull day, it's useless for indicating rocks. Green is much more visible for the same power, but the cheap green laser pointers I've had are dangerous junk (can massively exceed the rated power without warning when the rated power was already at the top end of what's sensible/allowed; sometimes don't turn on). This is in the UK where the whitewater season is winter and the rivers narrow. In somewhere like the Alps with sunny paddling you'd have no hope.

Perhaps more telling is that I've been on courses led by coaches who love having the latest gadgets and they've never used laser pointers.