Side-by-side cruise ship comparison · Updated January 2026
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across 5 categories
Size
Based on gross tonnage and length
Capacity
Based on passengers and crew
Modernity
Based on year built
Service
Based on passenger-to-crew ratio (lower is better)
Spaciousness
Based on gross tonnage per passenger (higher is better)
Costa Diadema
Costa Smeralda
Gross Tonnage
Costa Diadema
132,500 GT
Costa Smeralda
185,010 GT
Length
Costa Diadema
306 m
Costa Smeralda
337 m
Beam
Costa Diadema
37 m
Costa Smeralda
42 m
Passengers
Costa Diadema
3,724
Costa Smeralda
5,224
Crew
Costa Diadema
1,253
Costa Smeralda
1,682
Decks
Costa Diadema
—
Costa Smeralda
—
Year Built
Costa Diadema
2,014
Costa Smeralda
2,019
Space Ratio
Costa Diadema
35.6 GT/pax
Costa Smeralda
35.4 GT/pax
Passenger:Crew Ratio
Costa Diadema
2.97 :1
Costa Smeralda
3.11 :1
| Specification | Costa Diadema | Costa Smeralda |
|---|---|---|
| Overview | ||
| Cruise Line | Costa Cruises | Costa Cruises |
| Class | Diadema Class | Excellence Class |
| Status | active | active |
| Year Built | 2,014 | 2,019Winner |
| Dimensions | ||
| Gross Tonnage | 132,500 GT | 185,010 GTWinner |
| Length | 306 m | 337 mWinner |
| Beam | 37 m | 42 mWinner |
| Capacity | ||
| Passengers | 3,724 | 5,224Winner |
| Crew | 1,253 | 1,682Winner |
| Key Ratios | ||
| Space Ratio | 35.6 GT/paxWinner | 35.4 GT/pax |
| Passenger:Crew Ratio | 2.97:1Winner | 3.11:1 |
| Build | ||
| Builder | Fincantieri | Meyer Turku |
| Flag | Italy | Italy |
| IMO Number | 9636588 | 9785432 |
Costa Smeralda is the significantly larger vessel at 185,010 GT — 40% more than Costa Diadema's 132,500 GT. Built in 2019, Costa Smeralda is 5 years newer — an advantage for travellers seeking modern amenities and design. Costa Diadema edges ahead in service with a passenger-to-crew ratio of 3.0:1, meaning more crew per guest.
| Category | Winner |
|---|---|
| Size | Costa Smeralda |
| Capacity | Costa Smeralda |
| Modernity | Costa Smeralda |
| Service | Costa Diadema |
| Spaciousness | Costa Diadema |
Bottom line: Costa Smeralda wins more categories (3 vs 2), making it the stronger all-round choice based on current data.
Costa Diadema
Large 3,724-guest capacity offers competitive pricing
Well-suited for cruise newcomers
3,724 passengers means tons of activities
Comfortable atmosphere for two
Costa Smeralda
Large 5,224-guest capacity offers competitive pricing
5,224 passengers means tons of activities
Built in 2019 with modern facilities — great for a first cruise
Comfortable atmosphere for two
Free cancellation on most rooms
Bundle & save on your cruise trip
Medical, trip cancellation & luggage cover
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| Draft | 8.5 m | 8.5 m |
| Decks | — | — |
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