Halcyon Slim Closed Alert Marker 6' SMB
Halcyon 6' SLIM Closed Alert Marker SMB

Halcyon Slim 6' SMB

Sale price£155.00

The Halcyon Slim 6' SMB has an integrated pressure-relief valve and no-lock connector allowing them to be deployed easily from depth.


Dispatched in 1 to 2 days

Contact Form & Details

How can we help?

If you need to contact us for any issue or assistance, you can do so online by filling out the online Contact Form, emailing us at sales@dirdirect.com or calling us on +44(0)1305 824 555. If it's about a purchase you've made for us please also include your order number.

Our brick-and-mortar store Underwater Explorers based on Portland, Dorset is staffed 7 days a week, including weekends and bank holidays. As it's an active store visited by divers from around the country and world regularly, if we can't make it to the phone for any reason please leave a message and we'll get back to you asap.

Any queries are usually answered the very same day and at most within 24 hours.


Why Portland?

We’re located on the Isle of Portland (in Dorset) because Portland has been one of the most popular scuba diving locations in the United Kingdom even before we set up operations here back in the year 2000.

On one side, we’re minutes away from the sheltered waters of Portland Marina and Harbour, while on the other, it’s just a brief walk to reach our famous scuba diving destination Chesil Cove and start of the 16-mile-long Chesil Beach.  

Portland’s location makes it ideal for scuba diving, freediving, snorkelling and other surface water sports activities. 

Check out how many wrecks we have around here by clicking on Scimitar Diving's Wreck & Dive Sites chart!

Alongside dive clubs, many instructors and dive schools travel here to train and offer scuba diving certification ranging from open water diver to mixed-gas tech diving or rebreather diving levels.

Whether you’re doing a boat dive from Portland Marina or Castletown or a shore dive at Chesil Cove, Portland is well known for offering many possibilities: Reef diving to wreck diving and night diving, underwater photography or underwater videography. Anything other than cave diving is possible here.

Likely being the best-stocked diving shop in the UK, at Underwater Explorers we offer in-store scuba diving equipment advice and sales, as well as gas fills, to locals and visitors (read About Us).

But... If you’re googling “scuba diving shop near me” like some, look no further, there's DirDirect online.

Here at DirDirect, we list our cutting-edge equipment for worldwide delivery and we’ve got you covered whatever your level of diving: We’re your local dive store wherever you are in the world.

All that with over 20 years of experience especially in technical diving, from training to equipment, advice and sales.


Underwater Explorers, Unit 1, Maritime Business Centre
Mereside, Portland, Dorset, DT5 1FD


The closed Halcyon Slim 6' SMB offers all the advantages of 1.8m long Halcyon's Super Big Diver's Closed Alert Marker with a narrower profile.

The SMB does not have an open bottom and is designed to be inflated by using an inflator hose through the fitted one-way valve connector.

The SMB has an integrated pressure-relief valve, allowing them to be deployed from depth. When deflated it fits in a pocket or backplate Halcyon MC Storage Pak.

Halcyon SMB provides maximum visibility and redundant flotation to support diving safety and peace of mind.

Halcyon Slim SMB features

  • Length: 6’ (1.8m)
  • 200 denier nylon
  • Lift capacity 5.5kg
  • Integrated over pressure relief valve, allowing them to be deployed from depth
  • Halcyon's No-Lock® connector for easy inflation
  • Easily inflated at depth
  • When deflated fit in a pocket or backplate MC Storage Pak
  • Marked with Coast Guard approved SOLAS reflective tape
  • Lifetime Warranty on RF-welded seams

What’s the best SMB?

This is a question we often get asked in-store, where it’s easy to show and demonstrate the many types of SMBs together with the dozens of reels we hold in stock. But online, where we list so many of these, it’s not always easy to decide on the best SMB that will suit your needs. While we appreciate everyone has their own configuration and needs, THIS ARTICLE aims to help you with your decision.

SKU: 14.040.003

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