Tier 3 indicators represent the third level of maturity within the Observatory's methodological framework and include indicators whose systematic implementation is not yet feasible due to methodological, organisational, or operational constraints. Although these indicators address important dimensions of sustainable tourism development, they require further methodological refinement, strengthened data collection mechanisms, or institutional arrangements before they can be applied consistently and reliably.
Their inclusion in the framework reflects the Observatory's long-term strategic vision and provides a roadmap for future actions aimed at enhancing data availability, methodological development, and the overall evolution of the indicator system.
| Coastal / Maritime | Code | Theme | Sub-theme | Indicator | Calculation Method | Tier |
| Coastal | 1.2.3 | Economic dimension | Local added value and employment | Share of tourism-related businesses (proxy for local added value of coastal tourism) | Share of the number of businesses in coastal tourism Business Sectors out of the total | Tier 3 |
| Coastal | 1.4.1 | Economic dimension | Investment in sustainable infrastructure | Public investment in tourism infrastructure (e.g. ports, trails, energy-efficient facilities) | Investment expenditure on tourism infrastructure | Tier 3 |
| Coastal | 1.4.2 | Economic dimension | Investment in sustainable infrastructure | Private investment in tourism infrastructure | Investment expenditure on tourism infrastructure | Tier 3 |
| Coastal | 1.4.4 | Economic dimension | Investment in sustainable infrastructure | Share of companies with innovations and green technologies in tourism (e.g. "smart" infrastructure) | Share of businesses with green innovation projects | Tier 3 |
| Coastal | 1.4.5 | Economic dimension | Investment in sustainable infrastructure | Share of unfinished constructions | Tier 3 | |
| Coastal | 2.2.3 | Social and cultural dimension | Cultural heritage and local identity | Share of visitable destination sites covered by a cultural heritage protection policy/plan | Number of cultural assets with a statutory protection policy/plan / Total recorded cultural assets | Tier 3 |
| Coastal | 2.3.1 | Social and cultural dimension | Accessibility and social inclusion | Share of beaches and marinas with accessibility infrastructure | Accessible beaches & marinas / Total beaches & marinas | Tier 3 |
| Coastal | 2.3.2 | Social and cultural dimension | Accessibility and social inclusion | Accessibility of tourism businesses for people with disabilities | Accessible businesses / Total tourism businesses | Tier 3 |
| Coastal | 2.4.2 | Social and cultural dimension | Human resources education and training | Share of employees with professional skills certifications (e.g. diving, seamanship, safety at sea) | Share of certifications per year | Tier 3 |
| Coastal | 2.5.2 | Social and cultural dimension | Safety and public health | Preparedness of local rescue and emergency services | Existence of plans, equipment and staff (checklist / adequacy index) | Tier 3 |
| Coastal | 3.1.4 | Environmental dimension | Natural resource management (energy, water) | Excess water consumption from tourism activities as a share of water reserves | Ratio of water consumption by tourism Business Sectors to water reserves | Tier 3 |
| Coastal | 3.1.5 | Environmental dimension | Natural resource management (energy, water) | Excess energy consumption from tourism activities as a share of supply capacity | Ratio of energy consumption by tourism Business Sectors to supply capacity | Tier 3 |
| Coastal | 3.2.4 | Environmental dimension | Waste and pollution management | Level of water, air and coastal pollution in tourism areas | Number of exceedances of statutory limits per pollutant and area per year | Tier 3 |
| Coastal | 3.2.7 | Environmental dimension | Waste and pollution management | Waste generated per tourist | Total volume of waste generated per tourist | Tier 3 |
| Coastal | 3.3.3 | Environmental dimension | Ecosystems and biodiversity | Beach visitor load | Number of visitors / kilometres of coastline | Tier 3 |
| Coastal | 3.3.5 | Environmental dimension | Ecosystems and biodiversity | Greenhouse gas emissions from tourism activities | CO₂eq emissions from tourism Business Sectors | Tier 3 |
| Coastal | 3.3.7 | Environmental dimension | Ecosystems and biodiversity | Coastal erosion | % of eroded coastal area out of the total coastal area | Tier 3 |
| Coastal | 3.5.1 | Environmental dimension | Environmental responsibility of businesses and visitors | Share of tourism businesses with "green" certifications | Share of certified businesses out of the total | Tier 3 |
| Maritime | 1.2.3 | Economic dimension | Local added value and employment | Share of tourism-related businesses (proxy for local added value of maritime tourism) | Share of the number of businesses in coastal tourism Business Sectors out of the total | Tier 3 |
| Maritime | 1.3.4 | Economic dimension | Cruise and marina performance | Cruise economic performance | Total cruise revenue / Total cruise passengers | Tier 3 |
| Maritime | 1.3.5 | Economic dimension | Cruise and marina performance | Revenue per cruise visitor (passengers / crew) | Tier 3 | |
| Maritime | 1.4.1 | Economic dimension | Investment in sustainable infrastructure | Public investment in tourism infrastructure (e.g. ports, trails, energy-efficient facilities) | Investment expenditure on tourism infrastructure | Tier 3 |
| Maritime | 1.4.2 | Economic dimension | Investment in sustainable infrastructure | Private investment in tourism infrastructure | Investment expenditure on tourism infrastructure | Tier 3 |
| Maritime | 1.4.3 | Economic dimension | Investment in sustainable infrastructure | Share of companies with innovations and green technologies in tourism (e.g. solar-powered craft, "smart" infrastructure) | Share of businesses with green innovation projects | Tier 3 |
| Maritime | 2.1.4 | Social and cultural dimension | Social acceptance and quality of life | Load on public spaces | Number of visitors / area of destination point of interest (hotspot) | Tier 3 |
| Maritime | 2.1.5 | Social and cultural dimension | Social acceptance and quality of life | Traffic load | Number of cruise support vehicles / registered vehicles in the destination | Tier 3 |
| Maritime | 2.1.6 | Social and cultural dimension | Social acceptance and quality of life | Transport load | Travel time from the point of arrival to the hotspot / distance in kilometres | Tier 3 |
| Maritime | 2.2.2 | Social and cultural dimension | Cultural heritage and local identity | Share of visitable destination sites covered by a cultural heritage protection policy/plan | Number of cultural assets with a statutory protection policy/plan / Total recorded cultural assets | Tier 3 |
| Maritime | 2.5.2 | Social and cultural dimension | Safety and public health | Preparedness of local rescue and emergency services | Existence of plans, equipment and staff (checklist / adequacy index) | Tier 3 |
| Maritime | 3.1.2 | Environmental dimension | Natural resource management (energy, water) | Water consumption per berthed craft in marinas | Total water consumption per berthed craft in marinas | Tier 3 |
| Maritime | 3.1.3 | Environmental dimension | Natural resource management (energy, water) | Energy consumption per berthed craft in marinas | Tier 3 | |
| Maritime | 3.1.4 | Environmental dimension | Natural resource management (energy, water) | Share of tourism businesses using renewable energy sources | Businesses using RES / Total tourism businesses | Tier 3 |
| Maritime | 3.1.7 | Environmental dimension | Natural resource management (energy, water) | Excess water consumption from tourism activities as a share of water reserves | Ratio of water consumption by tourism Business Sectors to water reserves | Tier 3 |
| Maritime | 3.1.8 | Environmental dimension | Natural resource management (energy, water) | Excess energy consumption from tourism activities as a share of supply capacity | Ratio of energy consumption by tourism Business Sectors to supply capacity | Tier 3 |
| Maritime | 3.2.1 | Environmental dimension | Waste and pollution management | Share of air pollutants retained on cruise ships | NOx (nitrogen oxides) / cruise ship or per cruise passenger SOx (sulphur oxides) / cruise ship or per cruise passenger | Tier 3 |
| Maritime | 3.2.3 | Environmental dimension | Waste and pollution management | Waste generated per cruise visitor | Total volume of waste generated per cruise visitor | Tier 3 |
| Maritime | 3.2.4 | Environmental dimension | Waste and pollution management | Waste generated per yachting & day-boat visitor | Total volume of waste generated per craft visitor | Tier 3 |
| Maritime | 3.2.8 | Environmental dimension | Waste and pollution management | Level of water, air and coastal pollution in tourism areas | Number of exceedances of statutory limits per pollutant and area per year | Tier 3 |
| Maritime | 3.3.5 | Environmental dimension | Natural resource management (energy, water) | Greenhouse gas emissions from tourism activities | CO₂eq emissions from tourism Business Sectors | Tier 3 |
| Maritime | 3.3.7 | Environmental dimension | Natural resource management (energy, water) | Coastal erosion | % of eroded coastal area out of the total coastal area | Tier 3 |
| Maritime | 3.3.8 | Environmental dimension | Natural resource management (energy, water) | Existence of a local coastal adaptation plan | Tier 3 | |
| Maritime | 4.2.3 | Governance | Participation, communication, promotion and partnerships | Businesses communicating sustainability actions (website, signage, reports) | Businesses communicating sustainability actions | Tier 3 |