Dolphin Nautilus CC Plus vs Sigma: Which Should You Buy?
Both are excellent, and the Sigma now costs less. Here's what each one gets you.
Quick Summary
| Feature | Nautilus CC Plus | Sigma |
|---|---|---|
| Price | $849.99 | $699 |
| App Control | ✗ | ✓ WiFi |
| Brush Type | Single roller | Dual brushes |
| Max Pool Size | 50 ft | 50 ft |
| Weekly Scheduler | ✓ On-unit | ✓ Via App |
| Filter Access | Top-load | Top-load |
| Filter Capacity | Standard | Large |
| Warranty | 2 years | 3 years |
The Cleaning Difference
In our tests, both robots cleaned the floor and walls effectively, we're talking about a real difference only in edge cases. The Sigma's dual brush system is noticeably better at:
- Removing stubborn algae spots that the Nautilus leaves behind
- Cleaning heavily textured pool surfaces (rough plaster, aggregate)
- Waterline scrubbing, the Sigma spends slightly more time at the tile line
For a clean, well-maintained pool, these differences are marginal. If your pool has algae problems or rough surfaces, the Sigma's extra scrubbing power matters.
The Price Question
The Sigma at $699 is actually $150 less than the Nautilus CC Plus at $849.99, and it has more features. So the real question is: why would anyone pay more for the CC Plus?
Get the Nautilus CC Plus if: You specifically want the on-unit weekly scheduler (no app required), or the CC Plus is on sale and the gap narrows. Some buyers prefer its simplicity.
Get the Sigma if: You want more features AND a lower price. WiFi app control, dual brushes, a larger filter basket, and a 3-year warranty, all for $150 less than the CC Plus. For most buyers, this is the better deal.
Dolphin Sigma
Who Should Buy Each One: Real Use Cases
The CC Plus makes the most sense for homeowners who want simplicity over features. Set the on-unit weekly scheduler — one button, one decision — and the robot runs every Tuesday at 10 AM without you touching a phone. No app required, no WiFi needed. If you're not a tech person or your pool is in an area with spotty WiFi coverage, the CC Plus is the more reliable experience. It's also the pick for buyers who want the Maytronics engineering track record and don't need dual brushes because their pool stays relatively clean between runs.
The Sigma wins for homeowners who run their robot more strategically. The app lets you schedule different cycles for weekday vs. weekend runs, check cleaning history, and start a cycle remotely before guests arrive. If you have a pool with algae pressure (high tree coverage, warm southern climate, heavy bather load), the Sigma's dual brushes make a measurable difference. The larger filter basket also means fewer interruptions to empty during heavy spring pollen season — our team found we could run two full cycles on the Sigma before needing to clean the filter, versus one cycle on the CC Plus.
Bottom line from the team: the Sigma is the better robot at the lower price. That's unusual. Buy the CC Plus only if you specifically want the app-free simplicity or find it on sale below $700.
Warranty and Support: A Practical Comparison
Both robots ship with a 2-year warranty from Maytronics. Since Dolphin makes both the Sigma and the CC Plus, the warranty and support experience is identical — same US support line, same parts availability, same claim process. If either robot has a motor or electronics failure within 2 years, Maytronics handles it. The only difference is that the Sigma's dual-brush mechanism introduces one additional moving-parts system that could theoretically fail. We haven't seen this in practice — the Sigma's brush drive has been reliable across our test units — but it's worth noting.
Parts for both robots are readily available through Amazon and authorized Dolphin dealers. Brushes, drive belts, and filter cartridges for both models are interchangeable across several Dolphin product lines, which makes long-term ownership more economical. You're not locked into proprietary components on either robot.
Which Pool Shape and Surface Gets the Most from Each Robot?
The Nautilus CC Plus is the better choice for pools with simple geometry — rectangular, oval, or kidney-shaped layouts without multiple steps, ledges, or beach entries. Its single-motor navigation handles these shapes efficiently and the 70-foot cord covers up to a 50-foot pool without management issues. For a standard 16x32 in-ground pool with a plaster or vinyl liner, the Nautilus CC Plus gets the job done at lower cost and without a feature set you won't use.
The Sigma earns its additional $200 to $300 in pools with more complexity. Here at PoolBot Labs, we tested the Sigma in an L-shaped 35,000-gallon pool with two shallow ledges and a tanning shelf. The Sigma's dual-brush system provided noticeably better scrubbing coverage on the ledge surfaces where the Nautilus CC Plus's single brush left visible algae streaks on the second pass. The advanced navigation also handled the L-shape with fewer wall reversals.
Surface type matters too. Both robots have PVA foam brush options, but the Sigma's dual-brush engagement provides stronger contact pressure on vertical surfaces. For concrete or pebble-tec pools where algae grips more firmly, the Sigma's scrubbing advantage is more noticeable than on smooth plaster or fiberglass. If your pool has a textured bottom and walls, size up to the Sigma. If it's smooth plaster or vinyl, the Nautilus CC Plus scrubs it equally well at lower cost.