Help me choose
Our pick: Dolphin Sigma
Dolphin Sigma is the Pool Express pick in this matchup. Dolphin Sigma cleans the floor, walls and waterline instead of stopping below the tile line. Dolphin Sigma includes filtration for sand, pollen and other fine debris.
Nautilus
Dolphin Nautilus CC Plus
Inground and above-ground pools up to 50 ft that need floor and wall cleaning.
ProLine
Dolphin Sigma
Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
Why Dolphin Sigma is our pick
Dolphin Sigma
Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
$2,399
Buy Dolphin SigmaDolphin Nautilus CC Plus or Dolphin Sigma: our take
Dolphin Nautilus CC Plus and Dolphin Sigma 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 Nautilus CC Plus is intended for inground and above-ground pools, while Dolphin Sigma is intended for inground pools. Both are rated for pools up to 50 ft. Dolphin Nautilus CC Plus cleans floor and walls; Dolphin Sigma cleans floor, walls, and waterline. Dolphin Nautilus CC Plus lists 2 active brushes and CleverClean navigation. Dolphin Sigma lists 2 active brushes, SmartNav 3.0 with gyroscope navigation, and Triple commercial-grade DC motors.
Filtration and debris
Dolphin Nautilus CC Plus includes Standard filter; Dolphin Sigma includes Standard filter and NanoFilters. Dolphin Sigma has the clearer documented edge for fine silt, pollen and sand.
Controls and day-to-day ownership
Dolphin Nautilus CC Plus provides a weekly timer and smartphone control; Dolphin Sigma provides a weekly timer, smartphone control, and included remote control. Dolphin Nautilus CC Plus uses a 60 ft corded cable with an anti-tangle swivel, while Dolphin Sigma uses a 55 ft corded cable with an anti-tangle swivel. Dolphin Nautilus CC Plus is listed at 20 lb versus 24.6 lb for Dolphin Sigma; that 4.600000000000001 lb difference matters when lifting the robot from the pool.
Price, warranty and the decision
Dolphin Nautilus CC Plus is listed at $949 and Dolphin Sigma at $2,399; Dolphin Nautilus CC Plus is $1,450 less. Dolphin Nautilus CC Plus lists a 2.5-year warranty compared with 3 years for Dolphin Sigma. Pool Express pick: Dolphin Sigma. Dolphin Sigma cleans the floor, walls and waterline instead of stopping below the tile line. Dolphin Sigma includes filtration for sand, pollen and other fine debris. Choose Dolphin Nautilus CC Plus when it is the better fit for shoppers prioritizing the lower $949 starting price.
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 Nautilus CC Plus | Dolphin Sigma |
|---|---|---|
| Cleans the pool floor | Yes | Yes |
| Climbs and cleans walls | Yes | Yes |
| Scrubs the waterline | No | YesEdge |
| Fine-debris filter included | No | YesEdge |
| Large-debris filter | No | No |
| Automatic scheduling | Yes | Yes |
| Smartphone app | Yes | Yes |
| Anti-tangle swivel | Yes | Yes |
| 3-year warranty | No | YesEdge |
| 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 Nautilus CC Plus stands out
Dolphin Nautilus CC Plus is the better fit for shoppers prioritizing the lower $949 starting price.
- Is listed $1,450 lower
- Weighs 20 lb versus 24.6 lb
Where Dolphin Sigma stands out
Dolphin Sigma is the better fit for inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
- Cleans the floor, walls and waterline instead of stopping below the tile line
- Includes filtration for sand, pollen and other fine debris
- Adds gyroscope-assisted navigation
- Carries a 3-year warranty instead of 2.5 years
Dolphin Nautilus CC Plus vs Dolphin Sigma 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 Nautilus CC Plus | Dolphin Sigma |
|---|---|---|
| Best fit | Inground and above-ground pools up to 50 ft that need floor and wall cleaning. | Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris. |
| Starting price | $949 | $2,399 |
| Pool type | Inground, Above-ground | Inground |
| Maximum pool length | Up to 50 ft | Up to 50 ft |
| Cleaning coverage | Floor, Walls | Floor, Walls, Waterline |
| Power | Corded | Corded |
| Filtration | Standard filter | Standard filter, NanoFilters |
| Scheduling | Weekly schedule + app | Weekly schedule + app |
| App and remote | App control | App + included remote |
| Cable | 60 ft with anti-tangle swivel | 55 ft with anti-tangle swivel |
| Robot weight | 20 lb | 24.6 lb |
| Warranty | 2.5 years | 3 years |
Choose Dolphin Sigma
Dolphin Sigma is the Pool Express pick in this matchup. Dolphin Sigma cleans the floor, walls and waterline instead of stopping below the tile line. Dolphin Sigma includes filtration for sand, pollen and other fine debris.
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