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Tier-by-tier detail

Tier 0 – Awareness swims

Typical users School groups, eco-tourists, brand-new community projects.

What they actually do People snorkel over the reef with a guide. Picture cards show the difference between hard coral, soft coral and a bleached patch. No numbers yet—this stage simply builds excitement and reef literacy.

Cost & skill Mask, snorkel, laminated ID cards—well under 100 USD. A half-day talk is enough.

When to consider Tier 1 As soon as the group wants real numbers that can be tracked year to year.

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Tier 1 – Manual community surveys

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Typical users Local NGOs, dive clubs, small marine-reserve staff, Reef Check-style citizen-science teams.

What they do

1. Lay a 50-metre tape on the reef.
2. Volunteers jot down live-coral cover every 50 cm and count fish and invertebrates inside a belt next to the tape.
3. Results go into a spreadsheet or directly into MariMap when internet is available.

Cost & skill Startup gear runs 200–500 USD (tapes, slates, GPS, action cam). A two-to-three-day field course turns confident snorkellers or divers into reliable surveyors.

Strength Inexpensive; unbeatable for community engagement.

Limitation Accuracy depends on observer skill, and the small area sampled can miss patchy problems.

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Tier 2 – Semi-autonomous photo-transects

Typical users Regional environment offices, university field classes, citizen-science projects that have already logged Tier 1 data.

What they do

1. Divers tow a camera bar or fly a hobby drone to take overlapping photos along the same 50-m lines.
2. Images upload to MariMap.
3. Coral-AI and Fish-AI automatically tag corals, count colonies, measure percent cover and tally common fish.
4. Dashboards display trends within minutes or a few hours—complete with confidence bars.

Cost & skill About 3 000 USD buys a good action camera, tray or tow-sled and a basic drone. Each survey run costs roughly 1 000 USD (fuel, cloud time). One week of training covers photo-mosaics and Coral-AI use.

Strength You may map ten to twenty times the area per day, and the photo archive is a permanent audit trail.

Limitation Needs a laptop, steady electricity and basic internet to push imagery to the cloud.

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Tier 3 – Fully autonomous surveys

Typical users National park services, blue-carbon verification projects, offshore industries with strong compliance budgets.

What they do

1. An AUV (autonomous underwater vehicle) or compact ROV flies pre-programmed tracks, collecting 4K video, multibeam depth and even eDNA water samples.
2. On-board computers run Coral-AI / Fish-AI in real time; if bleaching or a crown-of-thorns spike appears, an alert pings managers immediately.
3. The system produces high-resolution 3-D maps of reef rugosity to millimetre accuracy.

Cost & skill Hardware begins around 25 000 USD; a typical mission costs 400–800 USD. Two weeks of vendor training turn staff into competent pilots and maintainers.

Strength Unmatched coverage, repeatability and speed—sufficient for carbon-credit audits or courtroom-quality evidence.

Limitation High capital cost, import permits and the need for skilled technicians.

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When to climb to the next tier

• Precision gap Manual counts swing by ±10 percentage points and conceal real change → Tier 2’s photos fix that.
• Spatial gap One 100 m transect barely samples a 10 ha lagoon → Drone mosaics (Tier 2) or AUV grids (Tier 3) solve it.
• Time gap Crown-of-thorns outbreaks can double in weeks → Near-real-time Tier 3 alerts are essential.
• Compliance gap Donors or carbon auditors demand photographic or AI-verified proof → Tier 2 usually suffices, Tier 3 for ultra-high resolution.

Whenever two or more gaps start to bite, it saves money in the long run to invest in the next tier.

Estimated budgets for each Tier

• Tier 0 under 100 USD total.
• Tier 1 200–500 USD to start; about 50 USD per survey.
• Tier 2 ~3 000 USD setup; roughly 1 000 USD per survey.
• Tier 3 at least 25 000 USD hardware (for purchase); 400–800 USD per mission.

Constant metrics across all tiers

No matter which tier you operate in, you will always record:

• Live-coral cover (our headline health metric).
• Species richness (how many species).
• Abundance (how many individuals of each).
• Biodiversity index—often the Shannon number, written plainly as
• H′ = – Σ (p × ln p),
• where p is “this species’ share of all individuals.”
• Indicator populations—herbivorous fish, crown-of-thorns starfish, reef-building coral genera, etc.

What improves as you climb the tiers is accuracy, area, and speed, not the fundamental questions.
Start where your budget lets you; structure your data so it flows into MariMap; and move up a tier whenever precision, coverage or response time becomes critical.

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