Side-by-side cruise ship comparison · Updated January 2026
.jpg%26w%3D400&w=3840&q=75)
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
Island Princess
Gross Tonnage
Costa Diadema
132,500 GT
Island Princess
91,627 GT
Length
Costa Diadema
306 m
Island Princess
294 m
Beam
Costa Diadema
37 m
Island Princess
32 m
Passengers
Costa Diadema
3,724
Island Princess
1,970
Crew
Costa Diadema
1,253
Island Princess
900
Decks
Costa Diadema
—
Island Princess
—
Year Built
Costa Diadema
2,014
Island Princess
2,003
Space Ratio
Costa Diadema
35.6 GT/pax
Island Princess
46.5 GT/pax
Passenger:Crew Ratio
Costa Diadema
2.97 :1
Island Princess
2.19 :1
| Specification | Costa Diadema | Island Princess |
|---|---|---|
| Overview | ||
| Cruise Line | Costa Cruises | Princess Cruises |
| Class | Diadema Class | Coral Class |
| Status | active | active |
| Year Built | 2,014Winner | 2,003 |
| Dimensions | ||
| Gross Tonnage | 132,500 GTWinner | 91,627 GT |
| Length | 306 mWinner | 294 m |
| Beam | 37 mWinner | |
| Capacity | ||
| Passengers | 3,724Winner | 1,970 |
| Crew | 1,253Winner | 900 |
| Key Ratios | ||
| Space Ratio | 35.6 GT/pax | 46.5 GT/paxWinner |
| Passenger:Crew Ratio | 2.97:1 | 2.19:1Winner |
| Build | ||
| Builder | Fincantieri | Chantiers de l'Atlantique |
| Flag | Italy | Bermuda |
| IMO Number | 9636588 | 9187887 |
Costa Diadema is the significantly larger vessel at 132,500 GT — 45% more than Island Princess's 91,627 GT. Island Princess offers more personal space with a space ratio of 46.5 GT per passenger versus 35.6. Built in 2014, Costa Diadema is 11 years newer — an advantage for travellers seeking modern amenities and design.
| Category | Winner |
|---|---|
| Size | Costa Diadema |
| Capacity | Costa Diadema |
| Modernity | Costa Diadema |
| Service | Island Princess |
| Spaciousness | Island Princess |
Bottom line: Costa Diadema 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
Island Princess
47 GT/pax means plenty of quiet space
Well-suited for cruise newcomers
Premium onboard experience
Good range of onboard options
Free cancellation on most rooms
Bundle & save on your cruise trip
Medical, trip cancellation & luggage cover
We may earn a commission from partner bookings at no extra cost to you.
32 m |
| Draft | 8.5 mWinner | 8 m |
| Decks | — | — |
.jpg%26w%3D400&w=3840&q=75)
_in_Venice.jpg%26w%3D400&w=3840&q=75)
.jpg%26w%3D400&w=3840&q=75)