Diamond Lagoon Review

In This Review
Performance Tests | Firmness | Support & Sleeping Positions | Design | Materials | Comparisons | FAQs

At NapLab, we put each mattress to the test.

We test 10 different factors that impact the performance, comfort, and value of the mattress. We then take the results of that test and compare to every mattress we’ve tested to date.

Check out the full performance table below to see how this mattress ranks:

Factor	Diamond Lagoon	Average
Overall Score	8.74	8.57
Price (Queen)	$1,199	$1,332 (Hybrid only)
Cooling – Score	9.0	8.7
Sinkage – Depth	3.06″	2.14″
Sinkage – Feel	Extremely Deep	Moderate
Motion Transfer – Score	6.5	8.2
Motion Transfer – Acceleration	12.85 m/s²	8.78 m/s²
Response Time – Score	9.0	8.9
Response Time – Mostly Recovered	0.3 sec.	0.4 sec.
Response Time – Fully Recovered	0.9 sec.	0.9 sec.
Bounce – Height	13.12″	9.53″
Bounce – Feel	Very High	Moderate
Edge Support – Score	9.6	8.6
Edge Support – Sitting	3.75″	4.04″
Edge Support – Lying	Outstanding	Good
Sex – Score	9.7	8.4
Pressure Relief – Score	9.0	8.7
Comfort Layer Thickness	4.0″	4.1″
Mattress Thickness	13″	12.0″
Off-Gassing – Score	9.7	8.1
Off-Gassing – Smell	Minimal	Strong
Off-Gassing – Days	1 day	7 days
Company – Score	8.5	8.7
Trial	120 nights	177 nights
Warranty	20 years	25% have lifetime warranties, average of other 75% of mattresses is 13 years

How is the Diamond Lagoon Different?

Wondering how the Diamond Lagoon differs from the other mattresses in the Diamond collection? Or from other hybrids in general?

#1. Sustainable Materials

The Lagoon mattress uses cooling fabric made from recycled bottles, as well as the upcycled denim fabric border. It also incorporates recycled steel coils within the support layer.

If you’re looking for a mattress with a smaller environmental footprint, the Lagoon is a solid pick.

#2. Budget Pick

Because of the use of sustainable, recycled materials, the Diamond Lagoon is able to keep a lower price tag. They currently offer a Queen-sized mattress for under $1000, which is harder to come by in today’s mattress market.

Cooling performance on the Diamond Lagoon sustainable hybrid mattress was excellent. Throughout our tests, I did not feel any significant level of heat retention around my body.

The mattress breathed well and the sleeping surface remained comfortably cool.

The Lagoon uses 4.0” of comfort material on top of a pocketed coil support base. The layer of pocketed coils creates airflow and allows for better cooling for the foam comfort materials.

• Baseline Temperature – the temperature of the mattress before anyone lies on it
• Maximum Temperature (0 minute) – the temperature of the mattress after lying on it for 15 minutes
• Ending Temperature (5 minute) – the temperature of the mattress after being lied upon and having no one on it for 5 minutes

Looking at our objective data, we measured a maximum surface level temperature of 89.1°F. This is 0.5° cooler than the average max temperature (based on all of our tests to date) of 89.6°F.

The most telling performance indicator is the heat dissipation curve. From minutes 0 to 1 the temperature dropped from 89.1° to 84.6°, a decline of 4.5° F. This is notably better than the average 0 to 1-minute temperature decline, which is 3.8°.

The temperature continued to gradually decline up until minute 4. All factors considered, I’m pleased with the cooling performance on the Lagoon mattress.

Heat Dissipation Over Time

Time Elapsed	Temperature
1 minute	84.6°
2 minutes	83.1°
3 minutes	82.9°
4 minutes	82.2°
5 minutes	82.7°

The Diamond Lagoon has an extremely deep level of sinkage. In our tests, we measured 3.06” of pressure-point sinkage. This is significantly deeper than the average.

The level of sinkage is documented in the image below.

Across all of our tests to date, we have measured an average sinkage depth of 2.24”.

As a result, the Lagoon’s 3.06” is 0.82” deeper than average.

This level of sinkage creates a pronounced and exacting contour around the body. The quilted cover and foam layers provide a significant hug.

The contouring hug isn’t quite as sharp as more classic memory foam would be, but it leans far closer in that direction than it does in the direction of latex or other poly foams.

The Diamond Lagoon has a high level of motion transfer. In our tests, we measured a total acceleration range of 12.85 m/s². This is nearly double the average motion transfer of 6.50 m/s² (based on all of our tests to date).

The level of motion transfer is documented in the video below.

Looking at the motion transfer chart, which visualizes our accelerometer data, we can see the highest motion from 0.00 to 0.35. However, a moderately high level of motion remains until 0.70 seconds.

It is not until 1.06 seconds that motion returns to near zero levels. Both the total level of motion and motion duration are high. Mattresses with the shortest motion duration are able to fully disperse energy and return to near zero levels within 0.3 seconds.

Needless to say, the Diamond Lagoon is pretty far from that mark.

All of Diamond’s new 2022 mattress models (Lagoon, Sage, Tailor, and Flurry Lux) have been on the higher side. I expect Diamond is using the same coil unit for all of these mattresses.

While that specific pocketed coil base is solid in terms of support, edge support, and bounce, it leaves something to be desired for motion transfer.

The Diamond Lagoon mattress has a very fast response. In our tests, we measured 0.3 seconds for the mattress to mostly recover and 0.9 seconds for a full material recovery.

The mostly recovered response time is significantly faster than average, while the full material recovery is about average.

The level of responsiveness is documented in the video below.

Based on all of our tests to date, we have measured an average mostly recovered response time of 0.52 seconds and an average full material recovery time of 0.96 seconds.

The very fastest responding mattresses we’ve tested to date recover mostly in 0.2 seconds and fully in 0.3 seconds. While the Lagoon isn’t quite to that speedy level, it’s not far off, especially for the mostly recovered time.

Suffice to say, 0.3 seconds is plenty fast enough that most sleepers will never feel stuck by the Lagoon mattress.

It rapidly adapts and changes shape so you always feel well supported as you change positions during the night.

The Diamond Lagoon mattress has an extremely high level of bounce. In our tests, we measured a total bounce height of 13.12”.

This is 3.82” more bounce than the average bounce of 9.30” (based on all of our mattress tests to date). Typically, I like to see a bounce height in the 8-12” range.

8-12″ is enough to facilitate ease of movement and improve sex, but not so high that it creates significant motion transfer concerns.

As we saw in the motion transfer test above, motion transfer is high. No doubt, the high level of bounce coming off the coil unit is creating much of that motion transfer.

Needless to say, I do wish bounce was a bit lower, as it would also likely reduce motion transfer.

That said, it isn’t extraordinarily high. Just higher than I’d like it to be.

The level of bounce is also documented in the video below.

In my view, this level of bounce, while high, won’t’ be problematic for most sleepers, provided you are okay with the motion transfer.

Edge support on the Diamond Lagoon mattress is excellent for sitting and even better for lying. In our sitting edge support tests, we measured 3.75” of sinkage while sitting directly on the edge.

This is significantly better than the average.

Based on all of our tests to date, we have measured an average sitting sinkage depth of 4.60”. Any sitting sinkage depth of 4.0” or less I consider to be excellent, so the Lagoon easily hits that mark.

The level of edge support while seated is documented in the images below.

While sitting directly on the edge the foam and coil unit felt fully supportive and there was no material collapse. Edge support while lying was even more impressive.

The level of edge support while lying is documented in the images below.

I felt exceptionally well supported when lying directly on the edge of the mattress.

The Diamond Lagoon uses a reinforced coil along the side rails of the mattress. This creates a more robust level of edge support that enables all sleeping positions to feel well supported at the very edge.

To score sex performance we look at a number of different factors that all play a role in quality sex. Three of the most important factors include:

In addition to the factors above, there are a few other things to consider as well, like pressure relief and cooling.

Here’s a look at our complete sex formula:

Sex Score Formula = (Bounce * 0.6) + (Edge Support * 0.2) + (Noise * 0.1) + (Pressure Relief * 0.05) + (Cooling * 0.05)

We use the following scores, plugged into the formula, to derive a sex score for each mattress.

Sex Factor	Factor Weight	Score	Rating
Bounce	65%	10	Extremely High
Edge Support	20%	9.1	Excellent
Noise	5%	10	Minimal
Pressure Relief	5%	9.0	Excellent
Cooling	5%	9.0	Excellent

This mattress has high bounce, great edge support, minimal noise, and a comfortable surface.

It checks all of the boxes and makes this one of the highest-scoring mattresses to date in this category.

Pressure relief on the Diamond Lagoon is excellent. The Lagoon creates a dramatic contouring hug around the body. Furthermore, the Lagoon creates an extremely deep level of sinkage.

In our tests, we measured 3.06” of sinkage depth. This sinkage depth combined with this type of exacting contouring hug is able to deliver fantastic pressure relief.

Some sleepers may find the sinkage depth deeper than they prefer. That said, in terms of raw pressure relief performance, the Lagoon has an ample comfort layer and sufficiently soft enough foams to create plenty of pressure relief.

Out of the box, the off-gassing was pretty minimal. The smell only lasted for about a day.

On average, mattresses tend to smell for about 3 days, so the Lagoon off-gassed faster than average.

The Diamond company has positive company policies and terms. They offer a 120-night trial period, a 20-year warranty, and free shipping.

Company Factor	Factor Weight	Score	Data
Trial Period	15%	8.0	120 nights
Warranty	10%	8.0	20 years
Shipping	5%	10	$0
Returns	20%	10	$0
Trust	50%	8.0	Good
Country of Origin	0%		USA

If the mattress ends up not working out, they also offer free shipping and free returns as well (within the continental U.S.)

The Diamond Lagoon sustainable hybrid mattress is a 5 out of 10 on the firmness scale.

This is a medium firmness and is suitable for a wide range of sleepers regardless of sleeping position preference or sleep or weight.

Support on the Diamond Lagoon is excellent. Throughout our tests and in all sleeping positions I felt fully supported.

The mattress uses a proven material layer design that provides sleepers with sufficient pressure relief, transitional support, and deep compression support.

Sleeper Weight	Stomach Sleepers	Side Sleepers	Back Sleepers
Under 150 lbs.	Yes	Yes	Yes
150-250 lbs.	Yes	Yes	Yes
250-300 lbs.	Yes	Yes	Yes

Given the design and material choices, I am confident in the support for sleepers up to 300 pounds.

Design

The Diamond Lagoon hybrid is a 13″ high mattress with medium firmness and designed with wide appeal to sweep across the spectrum of sleepers.

Materials

The Diamond Lagoon hybrid uses a blend of foam and coils with a quilted cover to hold it together. From top to bottom, layers include:

• 2.0″ quilted cover
• 1.0″ copper poly foam
• 1.0″ poly foam
• 8.0″ pocketed coils
• 1.0″ support foam

The Cover

The cover of the Lagoon is a 2.0″ quilted cover made of a cooling fabric from recycled bottles. There is a reinforced denim cording at the edge and upcycled denim fabric border along the sides.

There are also handles on the left and right sides of the mattress for moving the mattress.

The Comfort Layer

Beyond the quilted cover are two additional layers of foam. Both of these layers are a 1.0″ Certi-PUR-US certified poly foam.

The top layer is a copper poly foam for improved cooling performance, which seems to be impactful.

The second layer of poly foam is a more transitional foam layer to ease pressure between the comfort top layer and the support coils below.

The Support Layer

The support layer of the Lagoon consists primarily of the 8″ pocketed coil system. There is a thin foam layer below the coils for support and stability, but most of the support comes from the coils themselves.

Product Evolution

The Diamond Lagoon mattress was launched in August 2022 along with three other Diamond mattresses—the Tailor, Sage natural latex, and the Flurry Lux.

Given that this is such a new mattress, there have been no changes made to this mattress since its original release.

Other Mattresses to Consider

Not sure if the Diamond Lagoon is the best option for you? Check out these three top-rated hybrid mattresses below for alternative picks.

Frequently Asked Questions

Still have questions? Check out some of the top FAQs on the Diamond Lagoon hybrid mattress below and get the answers you’re looking for.