Sealife ReefMaster RM-4K


The SeaLife RM-4K Underwater Camera features brilliant 14mp still images and vivid 4K video in an incredibly small package that’s easy to hold and use alone or with attached lights like the SeaLife Sea Dragon.


Need some advice on this product? Speak to our experts Kieron or Conor
Call us today on 01924 444 888

The ultra-compact removable inner camera and a robust external housing that mounts easily to a light tray. The easy, 4-button control system makes catching the action an effortless process. The ReefMaster offers Wi-Fi sharing ability, so you can wirelessly preview, download and share pictures & videos to a smart phone or tablet with the free ReefMaster app from Google Play Store or Apple App Store.

The easy to hold ergonomic housing was especially designed for use underwater, while the housing is easy to hold and use even with one hand, the tough enclosure also features a unique closing system – a “Pressure Lock” thumb screw that exerts the optimal amount of pressure on the housings O-ring seal. The waterproof housing encases the small inner camera, and also stores a powerful drying agent called “Moisture Muncher” next to the camera that prevents internal fogging caused by heat and humidity trapped inside the housing.

With the expandable memory of the ReefMaster RM-4K, you can use Micro SDHC memory cards up to 128GB, ensuring you have room to shoot & save all of your video content. It also has a time lapse function – shooting at set time intervals and saves as video file or series of still images. For optimal results, especially when shooting 4K video, use Micro SDXC Class UHS Class 3 (U3) or Video Class 30 (V30) memory cards.

The compact RM-4K is easily expandable with popular SeaLife accessories, including one or two Sea Dragon Photo/Video/Dive lights, and available 10x close-up or super macro lens. Its 2.0” TFT colour LCD screen creates a sharp and easily visible display on the small camera.


    • 14 megapixel Panasonic® CMOS image sensor for sharp colourful pictures
    • 4K Ultra HD Video @ 30fps and 1080p HD video @ 60 fps
    • 40m/130ft compact underwater housing with removable inner camera
    • 140° Fisheye Lens – Get close to your subject and still fit everything into the picture
    • Underwater colour-correction modes– Underwater Deep for diving and Underwater Shallow for snorkelling
    • Easy 4 button controls for easy operation
    • Wi-Fi – wirelessly preview, download and share pictures/videos to smart phone or tablet with “SeaLife ReefMaster” app (free download from Google Play Store or Apple App Store)
    • Image Stabilization– Electronic stabilization reduces vibration and hand movement for smoother video recording
    • Expandable memoryusing micro SDHC/SDXC memory card up to 128GB
    • Waterproof to 130ft / 40m
    • Compact design for easy handling and lightweight travel
    • Focusfrom 12” (30cm) to infinity (10X Close-up Lens or Super Macro Lens optional accessory)
    • Time lapse shooting at set time intervals – saves as video file or series of still images
    • Removable Li-ion rechargeable battery – 900 mAh / 3.8V / 3.42Wh for 2+ hours video or 500+ images
    • 0” 230K Hi-res TFT colour LCD
    • Expandable with popular SeaLife accessories (One or two Sea Dragon Photo-Video-Dive Lights, Close-up Lens, Super Macro Lens)


      • Free App Name: ReefMasterin App & Play stores
      • Focal Length:5 mm (35 film equivalent = 14mm)
      • Focus type:Instant fixed-focus lens
      • Shutter response time: 30 seconds (AKA Shutter Lag)
      • Focus Range:12 inches to Infinity (30cm to infinity)
      • Field of View*:140° diagonal Fisheye Wide Angle Lens
      • Shutter speed:1/25 to 1/2000 second
      • Shooting modes:Single, Burst (3, 7, 15 or 30 photos @ 1 photo/sec), Time Lapse Photo and Time Lapse Video
      • White Balance (WB):Auto, Underwater Shallow, Underwater Deep, Daylight, Cloudy, Tungsten, Fluorescent
      • ISO:Auto, 100, 200, 400, 800, 1600 and 3200
      • Exposure Compensation:Exposure from -2.0 to +2.0 in 0.3 increments
      • Delay Timer:Off, 2 sec and 10 sec
      • LCD:0” TFT LCD colour display 230K resolution (240 * RGB * 320)
      • Memory:Micro SDHC/SDXC memory card up to 128GB (Sold separately). Important: Use Video Speed Class V30 (U3).
      • Read/write speed:10MB/s
      • PC connection:
        PC: Windows XP / 7  and up
        MAC: OS 10.8 and up
      • Output ports:
        1x USB 2.0 out (for charging battery and downloading to computer)
        1x Micro HDMI out (for direct connection to HDTV)
      • Battery:Removable  Li-ion battery (900 mAh / 3.8V / 3.42Wh)
      • Battery life:
        Still images: 2+ hours (Approx. 500+ images)
        Video: 1.5 hours at 1080p and 1.2+ hours at 4K
      • Wi-Fi range:100ft (33m) on land.
      • Waterproof:Individually depth tested to 130’ (60 m)
      • Shockproof:3ft / 1m
      • Buoyancy: Negative; -17 grams underwater
      • Operating temp:
        Land: 0°F to 120°F (-18°C to 50°C)

Underwater: +33°F to +110°F(.5 °C to 44°C)

      • Storage temp:-20°F to +140°F(-29°C to +60°C)
      • Tripod mount:Standard ¼-20 tripod threads
      • Weight:1 ounces (202 grams) UW housing w/ inner camera and battery.
      • Dimensions (LxWxH): UW Housing: 1.9” x 4.1” x 2.6” (4.9cm x 10.5cm x 2.6cm)
        Inner camera: 1.3” x 2.3” x 1.6” (3.3cm x 5.8cm x 4.1cm)


    • ReefMaster RM-4K inner camera
    • ReefMaster underwater camera housing
    • Wrist strap
    • USB cable 30”/75cm (USB-A to micro-B)
    • Moisture Muncher 1-capsule sampler

You can calculate the delivery costs for your order by entering a postcode when reviewing your basket. Don’t worry, this is an automated service and does not require you to register, or give any details.


Your Delivery

The range of products we offer means there is nothing standard about our deliveries.  We use a range of couriers, including DHL, UPS and Royal Mail.  While the site may state 3-5 days, most in stock items going to mainland UK locations will arrive at your door in 1-2 days.

On receipt of an order, the relevant specialist staff member will contact you to confirm the stock situation and expectation around shipping time.  This gives you a direct contact for any requests and advice that might be helpful.

When courier services are used, you can expect tracking information and estimated arrival times to be communicated via email.  However, always feel free to contact our staff at any point should you require assistance.

Need it quicker?  Please get in touch prior to placing an order.  We will always help where possible


Click & Collect

We’d love to see you in store!  There is no additional charge for collecting in person, and the delivery cost will be shown as free during the checkout process. By selecting collection in person you are agreeing to pick up your order from our address, shown below:


Robin Hood Watersports

152 Leeds Road


West Yorkshire

WF16 9BJ

United Kingdom


You will be contacted by one of our staff when the order is ready to collect.  Please do not visit the shop prior to receiving this communication.


Receiving your order

When you receive your item(s), please check to see if there is any damage.  Once the drivers manifest has been signed it voids any insurance claim. If you are unsure, please sign as "damaged", which will allow you/us to make a claim later on if required.

If you suspect that your goods are damaged please take the time to check the items with the driver present or refuse the package and ask the courier to return to sender.

If you have any further questions regarding delivery please contact us.

Sometimes things don’t go to plan and you might feel the need to arrange a return.  If you receive an order and find you have changed your mind, or the item just isn’t right for you, don’t worry. Goods can be returned for a refund within 30 days from the date of purchase (subject to our product exclusions). The process for both in store and mail order purchases can be seen below:

Postal Returns Procedure

If posting your return please email [email protected] for approval, as well as any advice required prior to sending.  You would then simply ship the unwanted goods to our 152 Leeds Road address, including a copy of your original receipt and information on the required course of action.

Purchases from store

If you bought goods from our Heckmondwike based store you may, at our discretion, be able to return items within 30 days for a full refund, as long as they have not been used and still have the original labels attached. Please bring the items back to the shop, together with your receipt. Any refund can only be made using the same method as the original transaction.

Goods must be returned in an unused, re-saleable condition, with their original packaging, and all labels still attached. They should also be securely packaged to ensure the contents are protected during transit. Our Returns Team will review all items to ensure they meet the criteria outlined in this policy. If an item is returned outside of our Returns Policy, we may be unable to process a full refund. We will contact you in such circumstances. 

Product Exclusions

There are some exclusions to our Returns Policy, as detailed below:

  • Personalised or customised items, such as custom canoes, made to measure drysuits etc.
  • Gift vouchers cannot be returned
  • Products that have been opened or unsealed cannot be returned
  • Products returned in an unsatisfactory condition cannot be returned
  • Products which have been damaged in return transit due to insufficient packaging cannot be returned

This Return Policy does not affect your statutory rights.

We hope that your next purchase from our store will be a long term one, so why not make use of our 0% finance offer.  The scheme is run through V12 and our experience, as well as that of our customers, has been excellent.


The 0% finance option allows you to spread the cost of your purchase over 6 or 10 months.  Given the bespoke nature of each application we prefer to discuss this with you, rather than automating the process online.  As such, once your basket is finalised and you are ready to apply please get in touch using [email protected], or by phone on 01924 444888.

We will confirm the availability and price of your order, then emailing a link to your custom application forms. Once completed, V12 notify our staff and you will then be contacted to settle the deposit and arrange a convenient delivery date.

Please refer to the representative example below.

Cash Price


Deposit Amount


Loan Term

10 months

Monthly repayments


Representative APR%

0% APR

Total amount payable


Rate of Interest (per annum)



Who can apply for finance?

You must:

• Spend over £300

• Make a deposit of at least 10%

• Be at least 18 years of age

• Have been a UK resident for 3 years or more

• Be able to make repayments by Direct Debit

• Be in regular employment* (minimum of 16 hours per week) including self-employment, or in a permanent residence with your partner who is in regular employment

*If you are retired and receive a pension or registered disabled and unable to work, V12 Retail Finance may ask for proof of sufficient income.

Credit is subject to status. Terms and conditions apply.

Under the Knives Act 1997 we have a responsibility to ensure this product is not sold to anyone under 18. As such, an age verified delivery service will be used, as well as further checks.
Check this box to confirm you are over 18 and agree to the special terms for this item.