Casio G’zOne Ravine Review

Introduction and Design

Casio continually remains one the main manufactures of Push-to-Talk phones for Verizon Wireless with their G’zOne series, from the Type-V and Type-S to the Boulder, Rock, and Brigade, which was introduced earlier this year. But unlike the Brigade that includes a full QWERTY keyboard, the new Casio G’zOne Ravine C751 is a traditional flip-phone in appearance that replaces the Casio Rock, though most of the features are retained, such as the good PTT quality and rugged Military design.

Included in the retail package is the Casio G’zOne Ravine C751 phone, 1140mAh battery, wall charger with detachable microUSB cable, and user guides. Unfortunately, the desktop charging cradle is no longer included, but it can be purchased separately. We did try the one from the Rock, and it will not work with the Ravine.


The Ravine keeps the Casio G’zOne look and feel throughout the device, with a 1.35” LCD display on the front that stays on continuously for easy viewing of the date, time, signal and battery levels, though we’re not fond of the burnt-orange colored ring that encompasses it. Like its predecessors, the Ravine is built to MIL-STD-810G for being resistant to conditions of water, shock, dust, immersion, vibration, salt fog, humidity, solar radiation, altitude, and low and high temperatures. It’s constructed out of hardened plastics and rubber, which gives a very durable and rugged feel to the device. All of the ports and openings also contain orange O-rings that help keep water out. Overall, the Ravine is a bit larger than the Rock and feels more bulky, though not as big as the Brigade, but is still suited for large hands. Along the sides are the volume rocker, voice command key, orange PTT key, 2.5mm headset jack, and microUSB port.

You can compare the Casio G’zOne Ravine with many other phones using our Size Visualization Tool.

On the back is the 3.2MP camera and LED flash, and the microSDHC memory card slot is hidden under the battery.

Unlike the Casio Rock that has a push-button on the hinge that releases and flips open the phone, the Ravine instead has to be opened manually. On the inside is a 2.2” TFT display with 240x320 resolution that supports up to 65K colors. In addition to being slightly larger than the 2.1” display used by the Rock, the images on the Ravine's screen also look better with more saturated and realistic colors. On the bottom is the standard d-pad for accessing the menus and the white backlit keypad. The numeric keys are somewhat hexagon in shape, but are smaller than the keys on the Rock, and are laid-out in an offset grid pattern, which makes it difficult to dial by touch alone, unless you are looking right at them. Because of this, we prefer the keypad on the Rock more as it is easier to use and the keys are larger.

Casio G’zOne Ravine 360 Degrees View:

Interface and Features:

The Casio G’zOne Ravine doesn’t really bring anything new to the table in terms of the included software, but we did notice using the software is faster than the previous models. The Main Menu is typical for a Verizon phone with categories for media center, contacts, messaging, recent calls, and settings & tools. There are also four themes included (white, wireframe, trek, and clash), as well as being able to display them in a tab, list, and grid view, where you can even replace and move menu items around on the grid. The external clock on the front display can also be inverted between black and white lettering.

You can store up to 1000 contacts with their name, multiple phone numbers, IM screen name, physical street address, ringtone and picture, as well as adding them to one of 999 speed-dial locations. There is also a separate PTT list where you can add up to 500 PTT names and numbers.

One thing we’re glad to see on the Ravine is the inclusion of the G’zGear program, which is also included on the Rock. It is located in the Tools menu, but can also be accessed directly by holding-down the CLR key. The Earth Compass shows a red line designating North and your current direction and degree heading (0-360), while World Nature tells you what Earth features are in your direction, such as the North Pole or Mt Everest. Walking Counter tracks your steps on a daily basis and shows them on a graph, including miles walked. Tides shows the current tide levels for cities around the US coast line and Current View displays an animated graphic of what the tide level would look like. Going into Sunrise/Sunset shows how many hours there are until the event, and even a day/night chart. Lunar Phase, as the name implies, shows the current phase of the moon (from full to new-moon), and Cosmic View displays the current location of the sun, moon, and earth in relationship to each other. The Star Gazer is similar to the Google Sky Map program, as it shows which stars and constellations are in your area based on your GPS location and direction. All of these features are nice as each one has a useful function for the outdoorsman.

The Casio G’zOne Ravine does come with an HTML browser, though we found it to be quite limited. When going to large sites, such as, it breaks the site up into smaller pages called Optimized View, which to us is not true HTML. You can choose to turn the Optimized View off, however in doing so most large sites will not fully load and it becomes difficult to navigate. Because of these browser limitations, we can only see using it on occasion; not on a daily basis.

The included 3.2MP fixed-focus camera on the Ravine does a better job than the Rock’s 2MP camera, but it does lack the autofocus that is found on the Brigade. Images that were taken outside using the Ravine produced adequate detail, but color accuracy is a bit off, as is the white balance. Bright areas also have a tendency of being overexposed, but the purple fringing that we saw with previous models appears to be gone. For capturing pictures indoors, image quality is reasonable as long as there is plenty of light, but in low-light conditions it is difficult to capture and the single LED flash doesn’t help much. Video recording is limited to 320x240 resolution at 15fps, so this is really only good enough for playing back on the phone, not on a large PC monitor. We were also able to playback an MP4 fila at 320x240 pixels on the Ravine.

Included memory on the device is 235MB, of which 197MB is available to the user. You can also install a microSD memory card up to 32GB to provide plenty of room for storing music and pictures.

Most other features remain the same that we’ve seen from other Verizon devices, such as the appointment calendar, text/picture/video messaging, MP3 music playback, VCast video streaming, and VZ Navigator for GPS guided driving directions. Other messaging options include Mobile Email, which will allow you to send and receive email through your standard POP or IMAP accounts, and Mobile IM for connecting to people in your AIM, Windows Live, and Yahoo! buddy lists. Also included on the Casio Ravine is a new program called Social Beat that allows you to connect to your accounts for Facebook, Twitter, MySpace, Google Talk, and GMail, as well as RSS. We tried it with Facebook and were able to view our feed, wall, inbox, and friend’s list. You can also post your current status and even upload a mobile photo.


The Casio G’zOne Ravine uses the Verizon EVDO Rev A. network for PTT connectivity. This allows the connection time between the devices to only be about 1 second or less, with voices also taking about 1 second to transmit. Using the PTT on the Ravine works quite well, as the orange PTT button is easy to find, and the stereo speakers on the bottom edge produce loud and clear voices. We also like the fact that it can be used with the phone open or closed.


Call quality through the earpiece speaker on the Casio Ravine was better than other G’zOne models, including the Brigade and Rock. Voices were clear and natural; without sounding distant. There also wasn’t any noticeable distortion, even when turning the volume all the way up to high. This was also true when using the speakerphone, as it was loud and clear on our end. People that we called also said that we sounded clear and natural on their end. Signal reception was good, as we didn’t drop any calls and had 4 bars of 3G and 3 bars of 1X showing in high-coverage areas.

The included 1140mAh battery is rated to provide up to 5 hours of talk time or 3 days of standby time on a full charge. During out testing, we were able to get up to 5 hours of continuous talk time or 4 hours of PTT usage with a full battery.


Overall, the Casio G’zOne Ravine is a nice upgrade to the Rock that came out last year. We are glad that it retains Military specs for durability, and its rugged design means that it should hold-up to almost anything you can through at it. But most importantly we’re glad that the PTT quality is quite good, since that is one of the Ravine’s primary functions, with loud and clear voices on both ends. If you need a good quality PTT device, the Casio Ravine is an excellent choice, but if you message a lot and require a QWERTY keyboard, then we’d still recommend the Casio Brigade.

Software on tested phone: C751M020

Casio G’zOne Ravine Video Review:


  • Military specs and rugged design
  • PTT performance
  • Good call quality and signal reception
  • Large external clock


  • More bulky than the Casio Rock
  • HTML browser is limited
  • Camera flash is useless

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