Door porthole or boat porthole
Updated: October 2026
You have one search word and four places the hole could go: an interior door, a cabin or shed side, a deck, or a wall. Door porthole or boat porthole is the split that stops a deck-hardware portlight landing in a hallway leaf. Amazon titles use porthole and portlight for the same ABS side window, so the shape is not the rule these pages keep. Match the flange to the surface. The rows are on the [porthole comparison](/hub/door-and-window-security/porthole). Peter F. used the listings saved on 19 October 2026. We did not lab-test a seal. A qualifying purchase can earn a commission at no extra cost to you.
You have one search word and four places the hole could go: an interior door, a cabin or shed side, a deck, or a wall.
You have one search word and four places the hole could go: an interior door, a cabin or shed side, a deck, or a wall. Door porthole or boat porthole is the split that stops a deck-hardware portlight landing in a hallway leaf. Amazon titles use porthole and portlight for the same ABS side window, so the shape is not the rule these pages keep. Match the flange to the surface. The rows are on the porthole comparison. Peter F. used the listings saved on 19 October 2026. We did not lab-test a seal. A qualifying purchase can earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Type | Opens | Seal | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  MLS MLS porthole B4000 | Interior-door porthole | Not stated as opening | n/a | 7.8 | about £77.42 | View offer |
 HouYeen HouYeen black opening porthole | Opening portlight | Yes, two fittings loosen | Rubber seals described as water-tight | 8.6 | about £30.99 | View offer | |
| Best value |  GAESHOW GAESHOW black boat porthole | Opening portlight | Yes | Rubber ring, waterproof claim | 8.0 | about £29.99 | View offer |
On this page
Door, side, deck, wall
A door porthole in this set is a pair of rings and a pane that clamp a leaf. It does not swing. A side window, often titled porthole and portlight on the same page, is an opening flange with a rubber seal. A deck hatch opens upward, with a stay. A wall porthole is furniture: a hinge, a small pane or a mirror, and a colour called antique brass.
amazon.co.uk sorts them that way. The MLS ranks in DIY & Tools, among latches and bolts. The ABS windows and the hatch rank in Sports & Outdoors, under deck hardware. The mirrors rank in Home & Kitchen. Deck hardware in an FD30 door is the wrong aisle before thickness. That stop is on porthole in a fire door. The only interior-door listing is the MLS B4000 at about £77.42, 250 mm, matte, stated for 40 mm plus or minus 2 mm. It does not open.
What an opening portlight is doing
The opening side windows are the HouYeen at about £30.99 and about 265 mm, the GAESHOW at about £29.99 and about 265 mm, the ZONADAH at about £35.99 and 215 mm, and the KKPLZZ at about £40.99 and 215 mm. They are ABS, with tempered glass around 4 mm, and the pages that mention screws say they are not included. The HouYeen is the top pick and opens when two fittings are loosened. The GAESHOW is the best value and opens. A rubber-seal line is the seller's waterproof claim, not a test report.
For a boat, the paperwork gap matters more than the thumbnail. The Recreational Craft Regulations 2017, Schedule 2, include prefabricated hatches and port lights sold separately for watercraft. BS EN ISO 12216 covers strength and watertightness on small craft up to 24 m. None of these twelve listings shows UKCA, CE, or that standard. GOV.UK's guide is about placing those components on the GB market, not about a shed. A yacht window sits in a regime these bullets do not document. A fire-door vision panel is a third job, and this portlight is the wrong object for both.
Hatch and wall decor
The Masyrt at about £313.29 is a push-out hatch, not a side window: aluminium, opening 457 by 327 mm, 6 mm smoke-grey tempered glass, a lockable handle and a stay stated for 0 to 90 degrees, at 4.2 kg. The thickness line says 15 mm or any thickness. That is not a measured clamp range. One review at 5.0, with no text, does not describe a deck.
Wall pieces leave the door decision. THE ANTIQUE HOUSE 9 inch clear unit is about £29.99, with about 13.5 cm of glass in a frame of about 23 cm, and UK reviews say it is not waterproof. The 12 inch clear piece is about £44.99. Medieval Replicas is about £37 and says indoor. The mirrors are the 9 inch at about £29.99 and the 11.5 inch at about £34.90. Use them for a cloakroom or a bar, not for a view through a door.
Shed and camper
UK buyers fitted the HouYeen to a shed with separate M4 bolts, called two shed windows watertight after silicone, and used it on a micro-camper and a camper back door opened for air. A UK GAESHOW note describes a bird hide. That is use, not an approval, and not a reason to cut a fire door. A shed is outside the recreational-craft regime. You still need a flat panel and bolts the box does not contain. One UK HouYeen buyer described a gap when the locks stayed on the inside. Silicone in that shed note is the buyer's method, not a certificate. A non-UK note of a refused camper approval is not UK law.
The MLS is for interior doors of about 40 mm, with matte laminated glass, and it does not open. The sample has no UK review text. If the camper must vent, stay with the portlight and accept the missing screws. If the house door must keep a fire certificate, stop. The named pick after this split is on best porthole.
Common questions
When do you buy the MLS rather than an ABS portlight?
When the hole is in a normal interior door of about 40 mm, you want a non-opening matte pane, and you want mounting material stated in the box. The MLS is about £77.42. Buy the ABS portlight when the panel is a shed, a camper side or a boat window that should open, and you will buy bolts yourself. The portlight does not state a door thickness.
Can the ABS portlight go in a shed?
UK reviews say yes for the HouYeen, with separate bolts and, in one note, silicone, and one GAESHOW note describes a bird hide. That is use, not a door specification and not a craft approval. Screws are not in those boxes. A summerhouse that needs a real seal is a poor match for the decorative hinged portholes, which UK reviews call not waterproof.
Is the Masyrt hatch a side window?
No. It is a push-out hatch, 18 by 12.9 inch, with a stay and an opening of 457 by 327 mm, at about £313.29. A side portlight in this set is the round ABS unit at about £30 to £41. The hatch's line of 15 mm or any thickness does not turn it into a door ring.
Why is the mirror in the same search?
Because the title says porthole. The 9 inch and 11.5 inch mirrors are wall hangings. They open and close as ornaments. They do not show the next room. Their Amazon aisle is wall mirrors, not door hardware. A cloakroom or a bar is the use those UK reviews describe.
Does a rubber-seal bullet mean ISO 12216?
No. BS EN ISO 12216 is the strength and watertightness standard for windows, portlights and hatches on small craft up to 24 m. These listings do not show that standard, or UKCA. A rubber ring on the listing is the seller's description. A shed is outside that regime. A yacht window can be inside it.
Can the door porthole go in a camper?
The MLS page states interior doors of 40 mm plus or minus 2 mm, and it does not open. A camper panel that needs ventilation wants the opening portlight instead, with the limit that UK reviews are not a vehicle approval. A non-UK story about a refused camper approval is not UK law.
Related pages
Sources
Public UK sources for glazing and craft rules, plus the MLS catalogue for the cut-out. Shelf figures are the amazon.co.uk files used on 19 October 2026. Euro prices in the catalogue are not the UK price.
- Approved Document K, protection from falling, collision and impact (retrieved 19 October 2026)
- Approved Document B, fire safety (retrieved 19 October 2026)
- British Woodworking Federation, machining of apertures (retrieved 19 October 2026)
- BS 8214:2026 commentary on fire-door glazing (retrieved 19 October 2026)
- Recreational Craft Regulations 2017, Schedule 2 (retrieved 19 October 2026)
- GOV.UK guide to the Recreational Craft Regulations 2017 (retrieved 19 October 2026)
- ISO 12216:2020 windows, portlights, hatches and doors (retrieved 19 October 2026)
- MLS catalogue, porthole 0180-0160-A6 (retrieved 19 October 2026)