I have a couple questions regarding the Heldigunner. I looked around and wasn't able to find this, sorry if its posted somewhere hehe, but since the Heldigunner is an aquatic Zoid, what is its maximum speed in the water and in the different types of soil? Furthermore, how deep can it dive and would it be too much to ask the maximum depths of the other aquatic Zoids too, (mainly an RP thing)? ^^

Edit: Oh yeah, what forms of detection is a burrowed Zoid susceptible to?

Does sonar work the other way around, allowing Zoids above the ground to detect underground Zoids?

Also, (for RP purposes), what is the approximate range of sonar in the different mediums?

The Heldigunner, being the best burrowing zoid, isnt really affected that much by different types of ground. Im pretty sure it can go through Sand, Loose Dirt, Packed Dirt and Dirt with a few rocks going at teh same speed.

The maximum depth of aquatic zoids is very deep, deeper than you would need to go. Lets just say you would die before your zoid.

Burrowing zoids are susceptible to acustic sensors, mukti sensors and sometime 3D sensors. THe 3D sensors only work if they are close to the surface or in dense terrain; which is because the ground will bulge upwards and disturb the surface.

Sonar above the ground can't use sonar to detect ground zoids because the sound waves will simply bounce of the dirt and register as a flat surface. The only way that would work is if you buried the area of your zoid which held the sensor, which isnt a good idea.

I dont really know the others.

I'd have to disagree on the depth part. Unless it's designed to go deeply, I'd say it wouldn't be able to go that far. I assume you know how quickly pressure changes under water in comaprison to air and earth? Just remember that the frame is more designed to take vertical forces more than sphereical ones.

For specific aquatic zoids, I'd say something like the Hammer Head and Warshark, being better in design would be abe to go very deep. I'm thinking not as deep as specialised subs, maybe a bit inferior. Also remember, pressure inside the zoid is different to pressure outside it.

I'd have to disagree with the sensor bit too. Acoustic would pick up something, though it'd most likely be very blurred/scrambled due to bouncing off the dirt so many times. Sound can go through dirt, it's just that it will reflect many different times.

As for using sonar above the ground, same thing as using acoustic to try and find a burrowing zoid but worse.

Seeing as you've asked for RP reasons though, here's a few things to help you out. In water, different saline concentrations and water temperatures can hide your zoids. Sonar waves have been known to bounce off the different types of water and show up multiples of the same thing onscreen. It was a tactic used during some World War to hide subs from boats and vice versa. Another thing to remember, is that air starts becoming poisonous beyond 200 feet and pure oxygen is toxic beyond 25 feet I think it was.

Just asking, but that hiding the sub, is that the same thing they used in the movie Submarine (i think that was it, comidy, very funny, instead of getting a nuclear powered sub, a captian gets the Sting Ray, an old rust bucket, and a makeshift crew)

In it, they took the Sub right inbetween the pepellers of an oiler i think, and it hid them from sonar.

I'm not too sure what you're saying so I can't really answer your question o.o

I'm not 100% confident of how a propeller disturbs water so I'm not sure.

Ahh, prop i think is another thing, ohh, you know the blades that are in the water that make a ship move? They turn and move the boat. The motion that does makes alot of air bubbles to form. IN big ships, like oil tankers, this creates alot of the air bubbles as well as a sort of vacume if it has two of them (i think, it is in the middle of the morning, might not even know what i am talking about) and if a sub were to go inbetween them, it kept them from the radar from the enemy sub.

Right. There's a certain limit, based on the design of the screw (props are for aircraft and speedboats ^_^) that its rotational speed can approach, before it starts doing that. It's called "cavitation," and results from the immense pressure changes in the water behind the screw causing the water to vaporize into bubbles of water vapor. Underwater, this makes a pretty loud *pop!* and is easily recognizeable. If you've ever read or seen The Hunt for Red October, then you'll recognize this phenomenon. The October's caterpillar drive system, in fact, was actually developed to combat just that.

Since all underwater Zoids use energy thrusters, rather than screws, for propulsion, cavitation is a non-issue, though I would imagine larger Zoids with more powerful engines to produce more of a booming noise as they go, particularly at high speeds. Smaller Zoids like the streamlined Sinker could slip through the water better, and Zoids that rely on body movement, like the Stealth Viper, would be the quietest of all, though they would still have their own, unique signature.