Cressi vs O’Three
Fast 7 mm Wetsuit Man vs 3mm Wetsuit – 3 X 3 GBS One Piece
Choose the exposure layer for your conditions before comparing the extras.
Cressi
O’Three
Scores are our editorial opinion of these models, based on features, suitability and ownership trade-offs—not hands-on test results. How we chose →
We’d pick the 3mm Wetsuit – 3 X 3 GBS One Piece.
We’d start with O’Three 3mm Wetsuit – 3 X 3 GBS One Piece. Our favourite for a 3 mm brief thanks to glued and blind-stitched seams and reinforcement at stress areas. Choose Cressi Fast 7 mm Wetsuit Man instead if its strengths are a better match: we would shortlist the 7 mm Fast when a thicker wetsuit is the brief and the shaped legs suit the diver. Thickness and fit come first. Our preference does not make a thinner suit a substitute for the insulation your conditions require.
Which one suits you?
Cressi Fast 7 mm Wetsuit Man

We would shortlist the 7 mm Fast when a thicker wetsuit is the brief and the shaped legs suit the diver. More thickness can mean more bulk; fit and personal warmth needs still decide.
Get to know this model →O’Three 3mm Wetsuit – 3 X 3 GBS One Piece

Our favourite for a 3 mm brief thanks to glued and blind-stitched seams and reinforcement at stress areas. It is still a 3 mm suit; choose a different thickness when the trip requires it.
Get to know this model →Specifications side by side
The details that matter, side by side. “Check with the brand” means we have not confirmed that detail.
| Detail | Cressi Fast 7 mm Wetsuit Man | O’Three 3mm Wetsuit – 3 X 3 GBS One Piece |
|---|---|---|
| Thickness | 7 mm | 3 mm throughout |
| ConstructionCheck with the brand | Double-lined neoprene with Ultra-Span arm panels | Check with the brand |
| Entry | YKK back zip with GlideSkin backing | YKK zipper with smooth-skin internal guard |
| CuffsCheck with the brand | Inner water-stop sealing rings | Check with the brand |
| Fit featuresCheck with the brand | Shaped legs and angled neck | Check with the brand |
| SeamsCheck with the brand | Check with the brand | Glued and blind stitched; stress areas taped |
| CutsCheck with the brand | Check with the brand | Men’s and women’s |
| KneesCheck with the brand | Check with the brand | PU-laminated reinforcement |
Showing all 8 specification rows.
What the differences mean when you buy
Thickness and intended exposure
Cressi Fast 7 mm Wetsuit Man
- Thickness
- 7 mm
O’Three 3mm Wetsuit – 3 X 3 GBS One Piece
- Thickness
- 3 mm throughout
Thickness is a useful starting specification, not a complete thermal rating. Fit, water movement, duration, repeated dives and individual response affect the protection required. Compare the actual suit thickness and role rather than transferring a number from an older listing. This comparison does not set a safe minimum water temperature.
Cut, entry and movement
Cressi Fast 7 mm Wetsuit Man
- Entry
- YKK back zip with GlideSkin backing
- Fit features
- Shaped legs and angled neck
O’Three 3mm Wetsuit – 3 X 3 GBS One Piece
- Cuts
- Men’s and women’s
- Entry
- YKK zipper with smooth-skin internal guard
Try the correct body cut and size, then check shoulder reach, bending and the entry arrangement. Front and back zippers can affect dressing convenience, but convenience should not override fit. Look for gaps and uncomfortable restriction. A men’s or women’s label alone does not establish that the measurements suit an individual body.
Seams, barriers and wear areas
Cressi Fast 7 mm Wetsuit Man
- Construction
- Double-lined neoprene with Ultra-Span arm panels
- Cuffs
- Inner water-stop sealing rings
O’Three 3mm Wetsuit – 3 X 3 GBS One Piece
- Seams
- Glued and blind stitched; stress areas taped
- Knees
- PU-laminated reinforcement
Read seam and water-barrier descriptions alongside the fit result. A pocket or reinforcement may be useful for a particular job, while a stretch-material name is not a measured flexibility advantage. Where seam details are missing, ask the manufacturer; do not treat absent research as proof that the suit lacks the feature.
A closer look at both
Fast 7 mm Wetsuit Man
The men’s Fast 7 mm is a double-lined full wetsuit with Ultra-Span arm panels, shaped legs and a YKK back zip. Inner cuff rings and a GlideSkin backing under the zipper are intended to limit flushing. It is the thicker Fast option to investigate when the 5 mm version does not provide enough protection for your planned dives.
What we like
We would shortlist the 7 mm Fast when a thicker wetsuit is the brief and the shaped legs suit the diver.
What would make us think twice
More thickness can mean more bulk; fit and personal warmth needs still decide.
More about the Fast 7 mm Wetsuit Man →3mm Wetsuit – 3 X 3 GBS One Piece
The 3 × 3 GBS is a full suit with 3 mm neoprene throughout, glued and blind-stitched seams, and internal tape at main stress areas. Stretch panels cover the shoulders, arms and sides. O’Three also adds a floating collar, internal zipper guard and reinforced knee and seat areas.
What we like
Our favourite for a 3 mm brief thanks to glued and blind-stitched seams and reinforcement at stress areas.
What would make us think twice
It is still a 3 mm suit; choose a different thickness when the trip requires it.
More about the 3mm Wetsuit – 3 X 3 GBS One Piece →Four checks before you place an order
- Select exposure protection for the planned conditions with appropriate local guidance, then compare suitable thicknesses.
- Try the actual cut and size through the movements needed to reach your equipment.
- Check the neck, cuffs, lower back and zipper area for uncomfortable restriction or obvious gaps.
- Confirm the exact model generation, especially outlet stock, and obtain size-exchange and return conditions.
Ask for a quote for the complete kit, including the accessories you need. That makes the price comparison much more useful.
Price, accessories and owning the equipment
Include any required hood, boots or other compatible exposure equipment when comparing the total purchase. A clearance suit can be good value only if it is the correct model, fits properly and has acceptable condition and return terms. Do not substitute a current premium model’s specifications for an older similarly named suit.
A replacement is easier to justify when it fixes fit, wear or a clearly assessed exposure need. A thicker suit is not automatically the more comfortable or suitable purchase. Follow the specific cleaning and storage instructions, and reassess equipment fit and configuration if changing exposure thickness.
How we scored these models & further reading
These are our subjective buying scores out of 100. We weigh the usefulness of the features, the intended diving or carrying job, and the compromises involved in owning the gear. They are not laboratory measurements, safety grades or customer averages. The verdict applies to the two named models, not everything either brand makes.
90–100: one of our first choices for the stated job. 80–89: a strong option with trade-offs. 70–79: a more specific fit. A different fit, camera, valve or dive plan can change which one you should buy.
Cressi Fast 7 mm Wetsuit Man
- Manufacturer details
- ScubaDownUnder: Cressi Fast 7mm Wetsuit
- Scuba Diving / ScubaLab: ScubaLab Reviews Nine 7mm Wetsuits
O’Three 3mm Wetsuit – 3 X 3 GBS One Piece
Product details and further reading →Questions worth settling
Are two suits of the same thickness equally warm?
No such conclusion follows from thickness alone. Their cut, water barriers, seams, condition and fit can differ, and the diver’s exposure needs matter. We do not have a controlled thermal comparison that establishes an overall warmth winner for this pair.
Which is the better buy for this particular comparison?
Thickness and fit come first. Our preference does not make a thinner suit a substitute for the insulation your conditions require. Cressi Fast 7 mm Wetsuit Man: More thickness can mean more bulk; fit and personal warmth needs still decide. O’Three 3mm Wetsuit – 3 X 3 GBS One Piece: It is still a 3 mm suit; choose a different thickness when the trip requires it.
Our pick is where we would start. Choose the other model if its fit or features better match your setup—especially where a camera, valve, boot or exposure suit needs an exact match.










