Mares Quad CI Dive Computer

The Mares Quad CI is a capable mid-range dive computer that pairs a large, readable display with a tilt-compensated compass and Bluetooth connectivity, covering the needs of most recreational divers without unnecessary complexity.

## Overview

Mares has positioned the Quad CI as the practical choice for divers who want more than a basic depth-and-time computer but do not need the multi-gas, colour-screen sophistication of flagship models from Shearwater or Suunto. At $690 AUD, it occupies the heart of the recreational dive computer market, competing directly with the Suunto Zoop Novo and the Cressi Leonardo. What distinguishes it from those competitors is the tilt-compensated digital compass — a feature that usually appears on computers costing significantly more — and a large segmented display that prioritises readability over aesthetic flair.

The Quad CI runs Mares' RGBM (Reduced Gradient Bubble Model) algorithm, which tends toward the conservative end of the decompression modelling spectrum. For recreational divers in Australia, where dive profiles frequently involve multi-level reef dives with relatively short bottom times, this conservatism provides a comfortable safety margin without being so restrictive that it cuts dives unreasonably short.

After a season of diving with the Quad CI across a range of Australian conditions — from warm, shallow reef dives on the Great Barrier Reef to cooler, deeper wreck dives at the ex-HMAS Adelaide and wall dives at Christmas Island — it proves itself a reliable and readable instrument that handles recreational diving confidently. Compared to the Suunto Zoop Novo at a similar price, the Mares offers the compass as a clear advantage. Against the Cressi Leonardo at roughly $350, the Quad CI justifies its higher price through better display readability, the compass, and Bluetooth log downloads.

## Key Features

- **Large segmented LCD display**: High-contrast display with large digits, readable in low visibility and at wide viewing angles - **Tilt-compensated digital compass**: Electronic compass that reads accurately regardless of wrist angle, eliminating the need to hold the computer perfectly level - **RGBM decompression algorithm**: Mares' Reduced Gradient Bubble Model with adjustable conservatism settings across three levels - **Air and nitrox modes**: Supports standard air and enriched air nitrox mixes up to 99% O2 - **Bluetooth connectivity**: Wireless log download to the Mares SSA app for dive log management and profile review - **Depth rating to 150 metres**: Sensor range well beyond recreational limits, providing headroom for accurate readings at all recreational depths - **Audible and visual alarms**: Configurable alerts for depth, time, ascent rate, decompression, and PO2 - **User-replaceable battery**: CR2430 battery accessible via a coin-operated back plate, no dealer service required for battery changes - **Backlight**: Illumination for low-light conditions and night diving - **Weight approximately 130 g**: Comfortable for all-day wear on the wrist

## The Good

- **Display readability is genuinely excellent**: The large segmented digits are the Quad CI's strongest practical feature. At depth in low visibility — common on many Victorian and South Australian dive sites — the display remains legible at a glance without squinting or bringing the computer close to your mask. This sounds basic, but poor display readability is the most common complaint about dive computers, and Mares has addressed it decisively - **Tilt-compensated compass is a genuine differentiator at this price**: Most dive computers under $800 either lack a compass entirely or offer a non-compensated version that requires holding your wrist perfectly level to get an accurate reading. The Quad CI's tilt-compensated compass reads accurately regardless of wrist position, which is invaluable for underwater navigation at sites like Fish Rock Cave or the Cod Hole where compass bearings matter - **RGBM algorithm provides conservative but practical dive profiles**: The RGBM model is well-suited to the kind of multi-level, multi-dive-day diving common on Australian liveaboard trips. It manages nitrogen loading conservatively without being excessively punitive on bottom time. During a four-day Cod Hole trip with three to four dives daily, the Quad CI's no-decompression limits remained practical and allowed full participation in every dive - **User-replaceable battery eliminates a common frustration**: Many dive computers require dealer service for battery replacement, which means downtime and cost. The Quad CI's coin-operated battery hatch allows replacement in minutes with a standard CR2430 cell, available at any electronics retailer - **Bluetooth log downloads work reliably**: The connection to the Mares SSA app is straightforward and consistent. Dive profiles download cleanly and the app presents them in a clear, useful format. After weeks of use, the pairing remained stable without the connection dropouts that plague some competitors - **Nitrox capability with adjustable PO2**: For divers using enriched air — increasingly common on Australian charter boats — the Quad CI handles nitrox mixes cleanly with clear PO2 monitoring and configurable alarms

## The Bad

- **Segmented display lacks the clarity of dot-matrix or colour screens**: While the large segments are readable, the segmented LCD format limits the amount and layout of information displayed simultaneously. Divers accustomed to the information density of a Shearwater Peregrine or Suunto D5 colour screen will find the Quad CI's display comparatively sparse. You get the essential data clearly, but secondary information requires button presses to access - **Menu navigation is unintuitive**: The button interface for accessing settings and secondary screens follows a logic that is not immediately obvious. Changing conservatism settings, adjusting alarms, or switching between dive modes requires consulting the manual the first few times. Once memorised, operation becomes routine, but the initial learning curve is steeper than it should be - **No air integration option**: The Quad CI is a depth-and-time computer only. It does not support wireless air integration via a tank transmitter. Divers who want tank pressure on their wrist computer will need to look at the Mares Genius or step up to a Shearwater or Suunto with transmitter compatibility - **RGBM conservatism can frustrate aggressive divers**: The RGBM algorithm's conservatism, while a safety benefit, can result in noticeably shorter no-decompression limits compared to Buhlmann-based computers. On repetitive deep dives — a common pattern at Australian wreck sites — the Quad CI may call you to ascend several minutes before a less conservative computer would

## Verdict

The Mares Quad CI is a well-executed mid-range dive computer that gets the fundamentals right. The large display is genuinely easy to read in all conditions, the tilt-compensated compass is a standout feature at this price, and the RGBM algorithm provides conservative but practical dive profiles for recreational diving. Bluetooth log downloads and user-replaceable batteries add practical convenience that matters over the life of the computer.

It is best suited to recreational divers who want a reliable, readable instrument with compass navigation capability without stepping into the $1,000-plus bracket of colour-screen computers with air integration. Divers who prioritise information density, air integration, or multi-gas capability should look at the Shearwater Peregrine or Mares Genius. But for the core recreational market — and that covers the vast majority of Australian divers — the Quad CI is a smart purchase at $690.

Star Rating: ⭐⭐⭐⭐☆ (4/5)