When you signup at bad site with email: abc@gmail.com password: abc If this is the same as you're gmail password they have instant access. You essentially told them your password.

Using Single sign on like Google or OpenId prevents this.

You have to consider what is the biggest threat. Is it more likely for google to be hacked or your machine getting a key logger? I don't know.

I would agree with you if you replaced "idea" with "well thought out idea." The reality is a lot of the people just have a simple idea and want some one to make it. I once had a guy ask me to make an Android app guitar tuner. I was to show the tone relative to the correct one as you played in real time as you tuned. They existed as a stand alone device, but he wanted an app. All he had was the idea. The UI design, the math behind it, everything else really was to be up to me, the programmer. He expected a 50/50 profit split. The professor is talking about these kind of people. But I agree. I great produce takes great design and great implementation. The people looking to rent the programmer only think they need an average programmer.

On the ocean you have a good chance of having 200m visibility so you're close enough to do all the things you mentioned. You don't have trees or hills or whatever in the way.

If the waves are super big you'll get blown 200m in a second anyway so more accuracy isn't going to help.

If you're trying to find a crab pot in the Fog then maybe it would help. But you're F'ed anyway. Turning around and backtracking on a boat is not that easy.

You could also argue that if the line from the pot to the buoy is longer than the dept of the water you're going to be off by a hundred feet easy.

It's not the same on the water, you're not looking for some geocache hidden under a rock. It's usually big orange things on the ocean if not other boats or ports.