Help me choose
A stronger Pool Express option
Dolphin M550 and Dolphin Nautilus CC Plus are compared feature by feature below. For a stronger Pool Express option, consider Dolphin Quantum. Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
M-Line
Dolphin M550
Inground pools up to 50 ft that need floor, wall and waterline cleaning with app control, Pick-Up and a caddy.
Nautilus
Dolphin Nautilus CC Plus
Inground and above-ground pools up to 50 ft that need floor and wall cleaning.
What we recommend instead
Dolphin Quantum
Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
$1,649
Buy Dolphin QuantumDolphin M550 or Dolphin Nautilus CC Plus: our take
Dolphin M550 and Dolphin Nautilus CC Plus are compared on pool fit, cleaning reach, debris handling, controls and ownership details. The recommendation is based on the job the robot must do—not a simple feature count.
Pool fit and cleaning reach
Dolphin M550 is intended for inground pools, while Dolphin Nautilus CC Plus is intended for inground and above-ground pools. Both are rated for pools up to 50 ft. Dolphin M550 cleans floor, walls, and waterline; Dolphin Nautilus CC Plus cleans floor and walls. Dolphin M550's documented cleaning system includes 2 active brushes and CleverClean navigation.
Filtration and debris
Dolphin M550 includes Basket and UltraFilter; Dolphin Nautilus CC Plus includes Standard filter. That gives Dolphin M550 the clearer documented edge for fine silt, pollen and sand. Dolphin M550 also has the better documented path for bulky leaves and larger debris.
Controls and day-to-day ownership
Both models provide a weekly timer and smartphone control. Dolphin M550 uses continuous corded power, while Dolphin Nautilus CC Plus uses a 60 ft corded cable with an anti-tangle swivel. Dolphin M550 is listed at 22.6 lb versus 20 lb for Dolphin Nautilus CC Plus; that 2.6000000000000014 lb difference matters when lifting the robot from the pool.
Price, warranty and the decision
Dolphin M550 is listed at $1,999 and Dolphin Nautilus CC Plus at $949; Dolphin Nautilus CC Plus is $1,050 less. Dolphin M550 lists a 3-year warranty compared with 2.5 years for Dolphin Nautilus CC Plus. Dolphin M550 and Dolphin Nautilus CC Plus each have a specific fit, but neither is the Pool Express pick for this job. Our better alternative is Dolphin Quantum. Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
Feature check: what each robot actually has
A green check means the feature is documented as included. A red X means it is documented as absent. A dash means the source does not make the feature clear.
| Feature | Dolphin M550 | Dolphin Nautilus CC Plus |
|---|---|---|
| Cleans the pool floor | Yes | Yes |
| Climbs and cleans walls | Yes | Yes |
| Scrubs the waterline | YesEdge | No |
| Fine-debris filter included | YesEdge | No |
| Large-debris filter | YesEdge | No |
| Automatic scheduling | Yes | Yes |
| Smartphone app | Yes | Yes |
| Anti-tangle swivel | Yes | Yes |
| 3-year warranty | YesEdge | No |
| No recharging between cycles | Yes | Yes |
| Built-in UV-C water treatment | No | No |
Unknown is not treated as “no.” Specifications come from the product pages, current catalog records and manufacturer material collected for this site.
Where Dolphin M550 stands out
Dolphin M550 is the better fit for inground pools up to 50 ft that need floor, wall and waterline cleaning with app control, Pick-Up and a caddy.
- Cleans the floor, walls and waterline instead of stopping below the tile line
- Includes filtration for sand, pollen and other fine debris
- Includes a large-debris bin or bag for leaves
- Carries a 3-year warranty instead of 2.5 years
Where Dolphin Nautilus CC Plus stands out
Dolphin Nautilus CC Plus is the better fit for shoppers prioritizing the lower $949 starting price.
- Is listed $1,050 lower
- Weighs 20 lb versus 22.6 lb
Dolphin M550 vs Dolphin Nautilus CC Plus specifications
Use pool fit first. Price and app control do not make up for a robot that cannot cover the length or surfaces you need cleaned.
| Specification | Dolphin M550 | Dolphin Nautilus CC Plus |
|---|---|---|
| Best fit | Inground pools up to 50 ft that need floor, wall and waterline cleaning with app control, Pick-Up and a caddy. | Inground and above-ground pools up to 50 ft that need floor and wall cleaning. |
| Starting price | $1,999 | $949 |
| Pool type | Inground | Inground, Above-ground |
| Maximum pool length | Up to 50 ft | Up to 50 ft |
| Cleaning coverage | Floor, Walls, Waterline | Floor, Walls |
| Power | Corded | Corded |
| Filtration | Basket, UltraFilter | Standard filter |
| Scheduling | Weekly schedule + app | Weekly schedule + app |
| App and remote | App control | App control |
| Cable | Not listed | 60 ft with anti-tangle swivel |
| Robot weight | 22.6 lb | 20 lb |
| Warranty | 3 years | 2.5 years |
Consider the stronger Pool Express option
Dolphin M550 and Dolphin Nautilus CC Plus are compared feature by feature below. For a stronger Pool Express option, consider Dolphin Quantum. Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
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