AquaSense 2 Ultra vs. Dolphin Sigma: Which Is Better

The AquaSense 2 Ultra is cordless and adds surface cleaning. The Dolphin Sigma is corded and better for simple scheduled cleaning. For a standard in ground pool, Sigma makes more sense. For floating debris, complex layouts, or above ground pools, the AquaSense 2 Ultra is the better choice.

AquaSense 2 Ultra vs. Dolphin Sigma at a Glance

Which One Makes More Sense for Your Pool?

Choose the AquaSense 2 Ultra if:

• your pool collects leaves, pollen, or oily surface film

• you want surface skimming and core cleaning in one robot

• your pool has shelves, ledges, baja shelves, or a more irregular layout

• you want cordless operation

• you need a cleaner that works in an above ground pool

Choose the Dolphin Sigma if:

• you have a standard in ground pool

• you want scheduled, low-touch cleaning

• floor, wall, and waterline cleaning are enough

• you would rather deal with a cord than a charging routine

• you want the simpler, lower-cost fit for a straightforward pool

What Do AquaSense 2 Ultra and Dolphin Sigma Clean

The Beatbot AquaSense 2 Ultra cleans five zones: the floor, walls, waterline, surface, and water column. That broader coverage matters if your pool still has floating leaves, pollen, sunscreen residue, or surface film after the walls and floor look clean. Its dual side brushes skim the surface, and the ClearWater™ system helps break down oils and fine particles that standard filtration can miss. In short, it handles both settled debris and floating debris.

The Dolphin Sigma focuses on three zones: the floor, walls, and waterline. Its three commercial-grade DC motors produce 4,500 GPH of suction, helping it stay planted on walls and clean consistently to the waterline. Its NanoFilter is built for fine debris like sand and pollen, which makes it a strong choice for routine in-ground cleaning.

What the Sigma does not do is skim the surface or clarify the water. If your pool sits under trees, gets heavy pollen, or often develops floating film, you will still need a separate skimmer or another surface-cleaning solution.

Which Is Easier to Live With, Cordless or Corded

The AquaSense 2 Ultra removes cable handling. When the cycle ends or the battery runs low, it surfaces automatically, and SmartDrain releases water before retrieval to reduce lift weight. It recharges on the dock in about 4.5 hours. The trade-off is routine: you still need to put it in, take it out, and dock it after each run.

The Dolphin Sigma is easier to leave on a schedule. Its weekly timer and myDolphin Plus app let it run without battery management or post-cycle docking. The 60-foot anti-tangle swivel cord reduces cable issues in most pools, and you can pause, recall, or steer it from your phone mid-cycle.

This comes down to charging routine vs. cord routine. If you want cordless handling and surface skimming in one robot, the AquaSense 2 Ultra has the advantage. If you want less day-to-day involvement, the Dolphin Sigma is easier to live with.

How AquaSense 2 Ultra and Dolphin Sigma Navigate the Pool

The Beatbot AquaSense 2 Ultra uses HybridSense, combining an AI camera, four ultrasonic sensors, two infrared sensors, and a water pressure sensor, powered by a 4-core Cortex-A7 CPU with 27 onboard sensors in total. It can detect organic debris during a cycle, return for pickup, and show a real-time 2D cleaning map in the app.

The Dolphin Sigma uses SmartNav 3.0 with a 3-axis gyroscope. It does not create a visual map, but it tracks orientation well, cleans in deliberate rows, and maintains strong wall-climbing consistency through the cycle.

In short, the AquaSense 2 Ultra offers more sensing and more route feedback, while the Sigma relies on a simpler, proven navigation system focused on consistent coverage.

Which Pool Types and Shapes Each Robot Supports

The AquaSense 2 Ultra works in both in-ground and above ground pools and supports concrete, vinyl, ceramic tile, and fiberglass surfaces. It also handles irregular shapes, kidney pools, multi-level platforms, and baja shelves. For platform cleaning, the elevated area should be at least 1 meter by 1 meter, with water depth over 13.7 inches.

The Dolphin Sigma is built for in ground pools up to 50 feet long. It works well in rectangular, round, kidney, and free-form pools, which covers most residential setups. Its main limitation is narrow stairs. It can struggle with steps under about 40 inches wide, which is worth checking in older or less standard free-form pools.

Which One Is Easier to Automate

The Dolphin Sigma is better for scheduled, low-touch cleaning. Its corded design means no charging, no docking after each cycle, and no need to check whether the robot is ready to run. You set the schedule, let it clean, and leave it alone.

The AquaSense 2 Ultra is better for more flexible, as-needed cleaning. If your pool use changes, debris comes and goes, or you prefer to run the robot based on current conditions, cordless operation is more convenient. 

Is the Higher Price Worth It

The Dolphin Sigma is the better value for a standard in ground pool. It covers the floor, walls, and waterline well, runs on schedule, and avoids the battery routine. For many pools, that is enough.

The AquaSense 2 Ultra costs more because it adds surface cleaning, water clarification, above ground compatibility, more advanced navigation, cordless operation, and a 3-year whole-unit replacement warranty. Those extras matter if your pool has floating debris, a more complex layout, or cleaning needs the Sigma does not cover.

FAQs

Does the Beatbot AquaSense 2 Ultra clean the water surface?

Yes. The AquaSense 2 Ultra uses dual side brushes and a submarine-style propulsion system to skim floating leaves, pollen, and other debris from the water surface.

The Dolphin Sigma does not include surface skimming.

Which robot handles fine sand and small debris better?

Both handle fine debris well, but in different ways. The Sigma's NanoFilter is designed to capture very fine particles such as sand, silt, and pollen.

The AquaSense 2 Ultra pairs strong suction with the ClearWater clarification system, which also helps address oils and finer suspended particles. For fine floor sediment, both are strong.

For broader water clarity support, the AquaSense 2 Ultra does more.

Can the Dolphin Sigma work in an above-ground pool?

No. The Dolphin Sigma is designed for in ground pools only.

The AquaSense 2 Ultra works in both in-ground and above ground pools across concrete, vinyl, ceramic tile, and fiberglass surfaces.

Which one has the better warranty?

Both offer 3-year coverage, but the structure is different.

The AquaSense 2 Ultra includes whole-unit replacement coverage, while the Dolphin Sigma uses a more standard manufacturer warranty approach.

Which one is easier to live with long term?

For buyers who want the least daily involvement, the Dolphin Sigma is usually easier to live with.

For buyers who care more about cordless flexibility, surface skimming, and broader cleaning coverage, the AquaSense 2 Ultra may still be the better fit.