The best robotic pool cleaner for an inground pool

An inground pool of ordinary size, with walls that need scrubbing as much as the floor does. Every robotic cleaner we track, judged against it on the pool length and wall climbing the makers publish, and then on what independent testers found when they ran the machines.

HomeRobotDataUpdated November 2, 202613 units judged from the makers’ own limitsListings checked November 2, 2026

For an inground pool 35 feet long, walls included, the Dolphin Nautilus CC Plus is the pick: Maytronics builds it for a pool set in the ground, rates it for one up to 40 ft, and states that it scrubs floor and walls in a single cycle, so this pool sits inside every published limit with room left. The Aiper Scuba S1 is the cordless way in, and the Dolphin Explorer E50 is the Dolphin that adds the waterline and carries the longer cover. Of 13 robotic pool cleaners judged here, 5 fit this pool, 3 do not, and 5 could not be judged at all, because their makers leave one or another of the limits this page turns on unpublished.

Our pick

Dolphin Nautilus CC Plus

$829 at Amazon

Three published facts decide fit and nothing else does: whether the maker builds the machine for a pool set in the ground, the pool length it rates that machine for, and whether it says the machine climbs walls. That leaves 5 units standing, so the order comes from what testers found, and the testers do not agree about the one at the top. The same cleaner is the best overall pick at Bob Vila, at Pool Research and at Popular Mechanics, and a disapproved one at The Pool Nerd, and we have left that disagreement standing rather than settle it for you. The same record sorts the rest: PoolBots calls the Dolphin Explorer E50 a strong all-around cleaner that climbs walls and waterlines well and no tester here marks it down, The Pool Nerd rates the Dolphin Nautilus CC Supreme disapproved on value and PoolBots doubts its price, and nobody in this page's record has put a Dolphin Sigma in a pool at all.

	Model	Pool type	Pool length, up to	Climbs walls	Scrubs the waterline	Cordless	Runtime	Weight	Warranty	Fit	Price
Our pick	Dolphin Nautilus CC Plus	in-ground	40 ft	yes	no	no	120 min	20.8 lb	1 year	Clears the published limits	$829 at Amazon
Also worth it	Aiper Scuba S1	in-ground	50 ft	yes	yes	yes	180 min	not published	2 years	Clears the published limits	$500 at Amazon
The upgrade	Dolphin Explorer E50	in-ground or above ground	50 ft	yes	yes	no	120 min	19.2 lb	2 years	Clears the published limits	$1,629 at Amazon

Against the same house
Our pick
Every model judged
Buying it right
Questions

Who this is for

Read on if your pool is permanently in the ground, close to the length this page assumes, and you want the walls cleaned rather than just the floor. Everything judged here is a self-contained robot that plugs in or charges up, not a pressure-side or suction-side cleaner hung off your filter system. If your pool comes down for the winter, read The best robotic pool cleaner for an above-ground pool instead: the makers rate those separately, and of the picks here only the Dolphin Explorer E50 carries a maker rating for both kinds of pool, while Aiper claims as much for the Scuba S1 and its own spec table does not. If you have narrowed it to the Dolphin, the Aiper and the Wybot, Aiper Scuba S1 vs. Dolphin Nautilus CC Plus sets those three side by side.

Your house, in the makers’ own terms

In-groundpool type

35 ftpool length

Climb the wallsasked for

Makers describe a pool cleaner in three published facts and this page checks each. Pool type comes first: the maker either sells the machine for an inground pool or it does not. Pool length is the longest pool the maker says the machine can keep on top of, not an area. Wall climbing is a yes or a no, and on some models a separate line says whether it also scrubs the waterline, the tile band at the surface. This pool is 35 feet, inground, walls included.

Against those three the field thins. The Dolphin Nautilus CC Plus is rated to 40 ft and both other picks to 50 ft, so all three clear this pool, the main pick with the least margin. Of everything judged, 3 units are out on one of those three, most because their makers sell them for above-ground pools. The near miss is the Dolphin Nautilus CC, the cheapest wall-climbing Dolphin here, out only because Maytronics rates it for a shorter pool; if yours is shorter, it comes back into play. A further 5 could not be judged at all, for different reasons: on some the maker never states a pool length, on others never whether the machine climbs walls or which pools it is for. What separates the shortlist is the waterline, the cord and the tester record.

your pool length: 35 ft

Dolphin Explorer E5050 ft

Aiper Scuba S150 ft

Dolphin Nautilus CC Plus40 ft

Aiper Scuba S1 Pro66 ft

Dolphin Nautilus CC Supreme50 ft

Dolphin Sigma50 ft

Dolphin Nautilus CC33 ft

Dolphin E1030 ft

Aiper Scuba SE30 ft

Pool length: each bar is a maker’s published limit, the picks in bold and the rest of the field beneath them; the dashed line is your house. A bar that stops short of the line is why a unit is excluded; 3 shown here do.

Adjust to your house. Change the numbers and this box re-judges the models we track against your house, with the same rules and the same maker figures. The picks and tables above stay on the page’s own house.

An inground pool 35 feet long, walls included, run against all 13 robotic pool cleaners we track: 5 clear every published limit this house turns on, 0 clear them at a limit or lack a feature this house wants, 3 miss one, and 5 could not be judged because the maker does not publish the limit. How we judge fit.

Our pickDolphin Nautilus CC Plus

The corded Dolphin that fits with margin, and most testers back

$829 at Amazon, November 2, 2026in-ground pool type40 ft pool length, up toclimbs wallsscrubs the waterline: no

Maytronics rates the Dolphin Nautilus CC Plus for a pool up to 40 ft and states that it scrubs both floor and walls in one cycle, so an inground pool 35 feet long, walls included sits inside both limits. It is corded, so it never stops halfway for want of charge, and it runs a default cycle of 120 min with a filter Maytronics grades ultra-fine. Bob Vila, Pool Research and Popular Mechanics each named it their best overall robotic pool cleaner. The Pool Nerd disapproves of it and PoolBots says it does not perform like the premium machine Dolphin markets, and those arguments are worth reading.

$829 at Amazon Full specs and sources

Price as of November 2, 2026; the listing we verified as the bare unit. Sold by The Pool Spot when we checked; we could not confirm whether that seller is an authorized dealer for the maker's warranty, so check before you buy.

What you give up

Maytronics' own spec sheet answers the waterline question with a flat no. The Pool Nerd found the machine reaches the waterline but will not scrub across it, so the band of tile at the surface stays your job. If that is the chore you are trying to be rid of, the Dolphin Explorer E50 is the other Dolphin here with that line answered, for a good deal more money.

Owner reports, tester figures, more photos and the listings we skipped are on the Dolphin Nautilus CC Plus page. Figures from maytronics.com. Recall screen: no US or Canada recall names this model, checked November 2, 2026.

Also worth itAiper Scuba S1

The cordless one, with a tester record to read first

$500 at Amazon, November 2, 2026in-ground pool type50 ft pool length, up toclimbs wallsscrubs the waterline

Aiper rates the Scuba S1 for a pool up to 50 ft and states that it climbs walls and cleans the waterline as well as the floor, so on the maker's own figures it covers more of this pool than the main pick does. It is the only cordless unit among the picks, so there is no cable to lay out and no power supply standing beside the water, and Aiper's cover of 2 years is longer than the Dolphin Nautilus CC Plus's and the same as the Explorer E50's. It is second because of what testers found when they checked those claims.

What testers said. The Pool Nerd: Disapproved; PoolBots: does not recommend it for serious pool owners. The Pool Nerd reviewed an earlier Scuba S1: it quotes Aiper's then-advertised 150 minutes. PoolBots does not name an edition; its unit ran 40 to 45 minutes and moved in a random pattern. We link the current edition, which Aiper rates for up to 180 minutes; no tester we can cite has reviewed it yet.

$500 at Amazon Full specs and sources

Price as of November 2, 2026; the listing we verified as the bare unit. Sold by AiperDirect, the maker's own storefront, when we checked.

Owner reports, tester figures, more photos and the listings we skipped are on the Aiper Scuba S1 page. Figures from aiper.com. Recall screen: no US or Canada recall names this model, checked November 2, 2026.

The upgradeDolphin Explorer E50

Longer cover, the waterline scrubbed, and a tester record that backs it

$1,629 at Amazon, November 2, 2026in-ground or above ground pool type50 ft pool length, up toclimbs wallsscrubs the waterline

Maytronics rates the Dolphin Explorer E50 for a pool up to 50 ft, lists the waterline among the surfaces it cleans where the main pick's sheet answers no, and covers it for 2 years against 1 year on the Dolphin Nautilus CC Plus. It is the lighter of the two Dolphins to lift out as well, 19.2 lb against 20.8 lb. PoolBots is the only tester here to have run one, and it calls the machine a strong all-around cleaner that climbs walls and waterlines well, scoring it well on waterline, coverage, ease of use and warranty and watching it scale walls with power. Buy it if the tile band at the surface is the chore you want gone.

$1,629 at AmazonFull specs and sources

Owner reports, tester figures, more photos and the listings we skipped are on the Dolphin Explorer E50 page. Figures from maytronics.com. Recall screen: no US or Canada recall names this model, checked November 2, 2026.

The competition

Every pool robot we track was judged against the same house. The verdict column names the maker limit that decided it.

Two units clear the same three limits and are not picks. The Dolphin Nautilus CC Supreme is the closer call, and it lost on the tester record, not on a limit: The Pool Nerd rates it disapproved, calling it a good cleaner that is not the smart buy at its price against Dolphin's own longer-warrantied lines, and PoolBots says it is hard to see how its price lines up with its performance. Maytronics covers it for the shorter term of the two, which is the strike The Pool Nerd names first.

The Dolphin Sigma clears everything too. The Pool Nerd approves it and calls it the best robotic pool cleaner you can buy, but its list price is more than three times the price of the pick.

Every unit, judged (13)

Model	Pool type	Pool length, up to	Climbs walls	Scrubs the waterline	Cordless	Runtime	Weight	Warranty	Price	Verdict
Aiper Scuba S1	in-ground	50 ft	yes	yes	yes	180 min	not published	2 years	$500	Clears the published limits
Dolphin Explorer E50	in-ground or above ground	50 ft	yes	yes	no	120 min	19.2 lb	2 years	$1,629 maker’s store $1,329, read November 2, 2026	Clears the published limits
Dolphin Nautilus CC Plus	in-ground	40 ft	yes	no	no	120 min	20.8 lb	1 year	$829	Clears the published limits
Dolphin Nautilus CC Supreme	in-ground	50 ft	yes	yes	no	150 min	24.6 lb	1 year	$1,449	Clears the published limits
Dolphin Sigma	in-ground	50 ft	yes	yes	not published	150 min	24.6 lb	3 years	$2,999 list	Clears the published limits
Aiper Scuba S1 Pro	in-ground	66 ft	not published	yes	yes	180 min	not published	not published	$1,200 list	Maker does not publish the limit the maker does not say whether it has wall climbing
Beatbot AquaSense 2	in-ground or above ground	not published	yes	yes	yes	240 min	23.1 lb	3 years	$849 list $1,298	Maker does not publish the limit the maker does not publish a pool length limit
Beatbot AquaSense 2 Ultra	in-ground or above ground	not published	yes	yes	yes	600 min	29.1 lb	3 years	$2,299 list $2,699	Maker does not publish the limit the maker does not publish a pool length limit
Wybot C1	in-ground or above ground	not published	yes	yes	yes	150 min	17.6 lb	2 years	$400 list $570	Maker does not publish the limit the maker does not publish a pool length limit
Wybot S2	not published	not published	yes	yes	yes	210 min	not published	not published	$1,000 list	Maker does not publish the limit the maker does not say which pool types it is for
Aiper Scuba SE	above ground	30 ft	no	no	yes	90 min	not published	not published	$150	Misses a published limit made for above-ground pools only aiper.com
Dolphin E10	above ground	30 ft	no	no	no	90 min	14.6 lb	2 years	$530	Misses a published limit made for above-ground pools only maytronics.com
Dolphin Nautilus CC	in-ground or above ground	33 ft	yes	no	no	120 min	14.8 lb	1 year	$699	Misses a published limit pool length limit is 33 ft; you need 35 ft maytronics.com

Buying it right

Each model page lists the similar Amazon listings we did not link and why: Dolphin Nautilus CC Plus, Aiper Scuba S1, Dolphin Explorer E50. How we match listings.

What this page can’t promise

Nothing on this page was tested by us. The measurements and verdicts come from named testers, and the build links each under the pick it belongs to. That matters more here than on most pages, because the testers disagree sharply about the main pick, line up against the cordless one, and only one of them has run the upgrade.

The makers do not always agree with themselves either. Aiper's page calls the Scuba S1 a cleaner for both above-ground and inground pools in its marketing copy, while the spec table underneath it lists inground only. Where a maker contradicts itself like that, this page says so rather than take the better number and move on.

This page reads a maker's pool-length rating, which is written for a plain rectangle, so it cannot see your corner steps, your tanning ledge, your main drains or your leaf load, and it cannot know how a battery that testers found short of its claim will do in a pool the size of yours.

Questions people ask

How big a pool can the Dolphin Nautilus CC Plus clean?

Maytronics rates it to 40 ft, and this pool is 35 feet. That rating is a length, not a surface area, so a narrow lap pool and a wide freeform pool of the same length are treated alike here, and a pool with a deep bowl and a ledge asks more of the machine than its length suggests. Both other picks are rated to 50 ft.

Do robotic pool cleaners clean the waterline?

Some state it and some do not, which is why the tables carry a waterline column: wall climbing and waterline scrubbing are two separate lines on a spec sheet. Among the picks, only the Aiper Scuba S1 and the Dolphin Explorer E50 state waterline scrubbing, and Maytronics answers no for the Dolphin Nautilus CC Plus. If the scum line at the tiles is your complaint, that column is the one to read across the whole field.

Dolphin Nautilus CC PlusOur pick