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 Pool Up
Inground and above-ground pools up to 30 ft that need floor and wall cleaning, with heavy leaves.
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 Pool Up or Dolphin Sigma: our take
Dolphin Nautilus Pool Up 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 Pool Up is intended for inground and above-ground pools, while Dolphin Sigma is intended for inground pools. Dolphin Nautilus Pool Up is rated for pools up to 30 ft; Dolphin Sigma is rated up to 50 ft. Dolphin Nautilus Pool Up cleans floor and walls; Dolphin Sigma cleans floor, walls, and waterline. Dolphin Nautilus Pool Up lists 1 active brush. Dolphin Sigma lists 2 active brushes, SmartNav 3.0 with gyroscope navigation, and Triple commercial-grade DC motors.
Filtration and debris
Dolphin Nautilus Pool Up includes Oversized leaf bag; Dolphin Sigma includes Standard filter and NanoFilters. Dolphin Sigma has the clearer documented edge for fine silt, pollen and sand. Dolphin Nautilus Pool Up also has the better documented path for bulky leaves and larger debris.
Controls and day-to-day ownership
Dolphin Nautilus Pool Up provides one-touch starts and power-supply controls; Dolphin Sigma provides a weekly timer, smartphone control, and included remote control. Dolphin Nautilus Pool Up uses a 40 ft corded cable, while Dolphin Sigma uses a 55 ft corded cable with an anti-tangle swivel. Dolphin Nautilus Pool Up is listed at 18 lb versus 24.6 lb for Dolphin Sigma; that 6.600000000000001 lb difference matters when lifting the robot from the pool.
Price, warranty and the decision
Dolphin Nautilus Pool Up is listed at $499 and Dolphin Sigma at $2,399; Dolphin Nautilus Pool Up is $1,900 less. Dolphin Nautilus Pool Up lists a 2-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 Pool Up when it is the better fit for shoppers prioritizing the lower $499 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 Pool Up | 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 | YesEdge | No |
| Automatic scheduling | No | YesEdge |
| Smartphone app | No | YesEdge |
| Anti-tangle swivel | Not listed | 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 Pool Up stands out
Dolphin Nautilus Pool Up is the better fit for shoppers prioritizing the lower $499 starting price.
- Includes an oversized leaf bag for bulky seasonal debris
- Includes a large-debris bin or bag for leaves
- Is listed $1,900 lower
- Weighs 18 lb versus 24.6 lb
Where Dolphin Sigma stands out
Dolphin Sigma is the better fit for pools up to 50 ft.
- Cleans the floor, walls and waterline instead of stopping below the tile line
- Includes filtration for sand, pollen and other fine debris
- Uses 2 active brushes instead of 1
- Can start on a weekly schedule without a manual launch before every cycle
Dolphin Nautilus Pool Up 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 Pool Up | Dolphin Sigma |
|---|---|---|
| Best fit | Inground and above-ground pools up to 30 ft that need floor and wall cleaning, with heavy leaves. | Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris. |
| Starting price | $499 | $2,399 |
| Pool type | Inground, Above-ground | Inground |
| Maximum pool length | Up to 30 ft | Up to 50 ft |
| Cleaning coverage | Floor, Walls | Floor, Walls, Waterline |
| Power | Corded | Corded |
| Filtration | Oversized leaf bag | Standard filter, NanoFilters |
| Scheduling | One-touch start | Weekly schedule + app |
| App and remote | Power-supply controls | App + included remote |
| Cable | 40 ft | 55 ft with anti-tangle swivel |
| Robot weight | 18 lb | 24.6 lb |
| Warranty | 2 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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