Help me choose
Our pick: Dolphin Sigma
Dolphin Sigma is the Pool Express pick in this matchup. Dolphin Sigma includes filtration for sand, pollen and other fine debris. Dolphin Sigma adds gyroscope-assisted navigation.
ProLine
Dolphin Sigma
Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris.
EON
Dolphin Nautilus EON 100
Inground and above-ground pools up to 50 ft with steps, benches or tanning ledges that need whole-pool cordless cleaning.
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 Sigma or Dolphin Nautilus EON 100: our take
Dolphin Sigma and Dolphin Nautilus EON 100 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 Sigma is intended for inground pools, while Dolphin Nautilus EON 100 is intended for inground and above-ground pools. Both are rated for pools up to 50 ft. Each cleans floor, walls, and waterline, so coverage alone does not separate them. Dolphin Sigma lists 2 active brushes, SmartNav 3.0 with gyroscope navigation, and Triple commercial-grade DC motors. Dolphin Nautilus EON 100 lists 2 active brushes and SmartMap navigation.
Filtration and debris
Dolphin Sigma includes Standard filter and NanoFilters; Dolphin Nautilus EON 100 includes Basket. That gives Dolphin Sigma the clearer documented edge for fine silt, pollen and sand. Dolphin Nautilus EON 100 has the better documented path for bulky leaves and larger debris.
Controls and day-to-day ownership
Dolphin Sigma provides a weekly timer, smartphone control, and included remote control; Dolphin Nautilus EON 100 provides a weekly timer and smartphone control. Dolphin Sigma uses a 55 ft corded cable with an anti-tangle swivel, while Dolphin Nautilus EON 100 uses cordless battery power. Dolphin Sigma is listed at 24.6 lb versus 22.1 lb for Dolphin Nautilus EON 100; that 2.5 lb difference matters when lifting the robot from the pool.
Price, warranty and the decision
Dolphin Sigma is listed at $2,399 and Dolphin Nautilus EON 100 at $899; Dolphin Nautilus EON 100 is $1,500 less. Dolphin Sigma lists a 3-year warranty compared with 1 years for Dolphin Nautilus EON 100. Pool Express pick: Dolphin Sigma. Dolphin Sigma includes filtration for sand, pollen and other fine debris. Dolphin Sigma adds gyroscope-assisted navigation. Choose Dolphin Nautilus EON 100 when it is the better fit for shoppers prioritizing the lower $899 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 Sigma | Dolphin Nautilus EON 100 |
|---|---|---|
| Cleans the pool floor | Yes | Yes |
| Climbs and cleans walls | Yes | Yes |
| Scrubs the waterline | Yes | Yes |
| Fine-debris filter included | YesEdge | No |
| Large-debris filter | No | YesEdge |
| Automatic scheduling | Yes | Yes |
| Smartphone app | Yes | Yes |
| Anti-tangle swivel | Yes | Not listed |
| 3-year warranty | YesEdge | No |
| No recharging between cycles | YesEdge | No |
| 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 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.
- Includes filtration for sand, pollen and other fine debris
- Adds gyroscope-assisted navigation
- Carries a 3-year warranty instead of 1 years
- Runs from continuous plug-in power without a recharge between cycles
Where Dolphin Nautilus EON 100 stands out
Dolphin Nautilus EON 100 is the better fit for shoppers prioritizing the lower $899 starting price.
- Includes a large-debris bin or bag for leaves
- Is listed $1,500 lower
- Weighs 22.1 lb versus 24.6 lb
Dolphin Sigma vs Dolphin Nautilus EON 100 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 Sigma | Dolphin Nautilus EON 100 |
|---|---|---|
| Best fit | Inground pools up to 50 ft that need floor, wall and waterline cleaning, with fine debris. | Inground and above-ground pools up to 50 ft with steps, benches or tanning ledges that need whole-pool cordless cleaning. |
| Starting price | $2,399 | $899 |
| Pool type | Inground | Inground, Above-ground |
| Maximum pool length | Up to 50 ft | Up to 50 ft |
| Cleaning coverage | Floor, Walls, Waterline | Floor, Walls, Waterline |
| Power | Corded | Cordless |
| Filtration | Standard filter, NanoFilters | Basket |
| Scheduling | Weekly schedule + app | Weekly schedule + app |
| App and remote | App + included remote | App control |
| Cable | 55 ft with anti-tangle swivel | Cordless |
| Robot weight | 24.6 lb | 22.1 lb |
| Warranty | 3 years | 1 years |
Choose Dolphin Sigma
Dolphin Sigma is the Pool Express pick in this matchup. Dolphin Sigma includes filtration for sand, pollen and other fine debris. Dolphin Sigma adds gyroscope-assisted navigation.
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