Help me choose
A stronger Pool Express option
Dolphin Nautilus EON 120d and Dolphin Premium 40 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.
EON
Dolphin Nautilus EON 120d
Inground and above-ground pools up to 50 ft that need whole-pool cordless cleaning with the least filter maintenance.
Premium
Dolphin Premium 40
Inground pools up to 50 ft that need floor, wall and waterline cleaning with app scheduling and a caddy.
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 Nautilus EON 120d or Dolphin Premium 40: our take
Dolphin Nautilus EON 120d and Dolphin Premium 40 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 EON 120d is intended for inground and above-ground pools, while Dolphin Premium 40 is intended for inground pools. Both are rated for pools up to 50 ft. Each cleans floor, walls, and waterline, so coverage alone does not separate them. Dolphin Nautilus EON 120d lists 2 active brushes and SmartMap navigation. Dolphin Premium 40 lists 2 active brushes and CleverClean navigation.
Filtration and debris
Both models include Basket and UltraFilter. Both have documented fine-debris media, so basket capacity and ease of cleaning matter more than fine-particle capability.
Controls and day-to-day ownership
Both models provide a weekly timer and smartphone control. Dolphin Nautilus EON 120d uses cordless battery power, while Dolphin Premium 40 uses continuous corded power. Dolphin Nautilus EON 120d is listed at 24.3 lb versus 18.6 lb for Dolphin Premium 40; that 5.699999999999999 lb difference matters when lifting the robot from the pool.
Price, warranty and the decision
Dolphin Nautilus EON 120d is listed at $1,199 and Dolphin Premium 40 at $1,629; Dolphin Nautilus EON 120d is $430 less. Dolphin Nautilus EON 120d lists a 1-year warranty compared with 2 years for Dolphin Premium 40. Dolphin Nautilus EON 120d and Dolphin Premium 40 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 Nautilus EON 120d | Dolphin Premium 40 |
|---|---|---|
| Cleans the pool floor | Yes | Yes |
| Climbs and cleans walls | Yes | Yes |
| Scrubs the waterline | Yes | Yes |
| Fine-debris filter included | Yes | Yes |
| Large-debris filter | Yes | Yes |
| Automatic scheduling | Yes | Yes |
| Smartphone app | Yes | Yes |
| Anti-tangle swivel | Not listed | Yes |
| 3-year warranty | No | No |
| No recharging between cycles | No | YesEdge |
| 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 EON 120d stands out
Dolphin Nautilus EON 120d is the better fit for shoppers prioritizing the lower $1,199 starting price.
- Is listed $430 lower
- Cleans floor, walls, waterline, steps and 8 in ledges
Where Dolphin Premium 40 stands out
Dolphin Premium 40 is the better fit for inground pools up to 50 ft that need floor, wall and waterline cleaning with app scheduling and a caddy.
- Carries a 2-year warranty instead of 1 years
- Runs from continuous plug-in power without a recharge between cycles
- Weighs 18.6 lb versus 24.3 lb
Dolphin Nautilus EON 120d vs Dolphin Premium 40 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 EON 120d | Dolphin Premium 40 |
|---|---|---|
| Best fit | Inground and above-ground pools up to 50 ft that need whole-pool cordless cleaning with the least filter maintenance. | Inground pools up to 50 ft that need floor, wall and waterline cleaning with app scheduling and a caddy. |
| Starting price | $1,199 | $1,629 |
| Pool type | Inground, Above-ground | Inground |
| Maximum pool length | Up to 50 ft | Up to 50 ft |
| Cleaning coverage | Floor, Walls, Waterline | Floor, Walls, Waterline |
| Power | Cordless | Corded |
| Filtration | Basket, UltraFilter | Basket, UltraFilter |
| Scheduling | Weekly schedule + app | Weekly schedule + app |
| App and remote | App control | App control |
| Cable | Cordless | Not listed |
| Robot weight | 24.3 lb | 18.6 lb |
| Warranty | 1 years | 2 years |
Consider the stronger Pool Express option
Dolphin Nautilus EON 120d and Dolphin Premium 40 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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