What to look for when buying DSMB and reel?

[MrsNic]

Hi. Please could i get some help? I need to buy a dSMB and reel. But have no clue what I need to get or what I'm looking for? Thanks. X

 

[TSandM]

Well, a lot depends on how and where you are going to use it.

In relatively calm water, a 1-meter bag may be fine, but offshore, a bigger and wider bag is probably better. For a small bag, to be deployed relatively shallow, you're better off with a spool, but below 70 feet, you may definitely want a reel instead.

For small bags, oral inflation works well. In warm water, almost any kind of inlet valve will do, but in cold water, I think the Halcyon bag with the metal inlet that can be used with an LP hose is the best -- not because you can use it with an LP hose, but because it has a wide metal flange on it that fits nicely in the corner of your mouth, and lets you inflate the thing with cold, numb lips, without losing all the air you try to blow into it.

For bigger bags, a duckbill opening on the bottom, or an LP hose fitting might be better, because it's hard to blow enough air into a big bag to get it to stand up well at the surface. For closed bags, and overpressure valve is pretty necessary; for duckbill or other open-bottom valves, not so much.

Some places, the color of the bag has meaning for the boat. It's important to know what the procedures are where you are doing your diving.

 

[cool_hardware52]

Hi. Please could i get some help? I need to buy a dSMB and reel. But have no clue what I need to get or what I'm looking for? Thanks. X

I'd suggest a finger spool vs a reel, but some folks use reels.

Keep in mind that a DSMB is not a lift bag or safety sausage. A true DSMB will include an Over Pressure Valve or OPV, usually near the bottom. This prevents it from bursting if launched at depth. A Surface Safety Sausage usually won't have an OPV.

I prefer a SMB that is easy to launch, doesn't require a lot of gas in it to be fully inflated at the surface, and doesn't require 1/2 of it be pulled back under water to keep it upright at the surface. SOLAS tape at the Top is a good thing.

Keep in mind that huge DSMBs are tough to launch when shallow because you need to add so much gas before you release it, otherwise it will be limp at the surface. Adding lots of gas makes holding depth tricky.

I prefer these https://www.deepseasupply.com/index.php?product=85

Full disclosure: I also design, and manufacturer them

The tapered design requires less gas, allows them to stand up eaiser, and limits the lift to about 5 lbs. That a benefit to the new SMB users if they get fouled in the line launching the bag, 5lbs is much less likely to drag you to the surface than a larger bag. If you have questions let me know.

Tobin

 

[dumpsterDiver]

Well, a lot depends on how and where you are going to use it.

In relatively calm water, a 1-meter bag may be fine, but offshore, a bigger and wider bag is probably better. For a small bag, to be deployed relatively shallow, you're better off with a spool, but below 70 feet, you may definitely want a reel instead.

For small bags, oral inflation works well. In warm water, almost any kind of inlet valve will do, but in cold water, I think the Halcyon bag with the metal inlet that can be used with an LP hose is the best -- not because you can use it with an LP hose, but because it has a wide metal flange on it that fits nicely in the corner of your mouth, and lets you inflate the thing with cold, numb lips, without losing all the air you try to blow into it.

For bigger bags, a duckbill opening on the bottom, or an LP hose fitting might be better, because it's hard to blow enough air into a big bag to get it to stand up well at the surface. For closed bags, and overpressure valve is pretty necessary; for duckbill or other open-bottom valves, not so much.

Some places, the color of the bag has meaning for the boat. It's important to know what the procedures are where you are doing your diving.

Good advice, however, I am pretty sure that the duck bill open ended bags would explode without an Over pressure relief valve on them.. they seal pretty well.

 

[cool_hardware52]

All the "Duck Bill" bags I've seen or used have been actual lift bags of fairly high capacity. A lift bag must have an OPV near the top of the bag to allow control of the ascent.

Tobin

 

[KevinNM]

Why do you need it? Is it for a particular class or for a particular dive? That would make it easier to figure out what you should look for.

 

[Ulfhedinn]

I use a DeepSeaSupply DSMB as a SMB and carry it 99% of the time but also have a Halcyon 4.5 ft (1.4m) BIG CC DAM in case I get lost at sea or need a backup BC in case of total bc failure.
I sue a 100' SS spool from SS Dive Spool - Dive Right in Scuba

 

[Doc Harry]

Reels jam and fall apart.

Finger spools don't.

 

[MrsNic]

Why do you need it? Is it for a particular class or for a particular dive? That would make it easier to figure out what you should look for.

it will be for when my husband and I decide to take a trip to the Irish sea as it is apparently a good place to dive and is fairly local to us (about an hours drive) also to use on quarry dives to practice using it.

 

[macado]

I recommend a finger spool and a true DSMB with an over pressure valve (OPV). If you're diving areas with potentially rough seas like the Atlantic, Irish Sea then a 6ft (1.8m) DSMB would be recommended.

Finger Spools are small, simple to use, won't jam and work well for launching an DSMB.

Tobin (cool_hardware52) gave a great example of the differences between an SMB and DSMB. As stated already, most SMBs do not have OVPs (over pressure valves) and are only meant to be inflated at the surface. A Delayed Surface Marker Buoy (DSMB) are meant to be inflated at depth.

I wrote this is another thread but I figured I'd paste it here.

SMB and DSMB are technically two different products but the term is often used interchangeably. It's all semantics. A DSMB typically has an (OVP) over pressure relief valve so that if it is shot from depth the pressure can safely escape. An SMB on the other hand does not have an OVP valve or an opening at the bottom where excessive air can escape/vent; It is designed to typically only be inflated at the surface.


In the event you do get separated from the group waiting until you surface to deploy your DSMB/SMB (whatever you want to call it) is a poor choice. You want to give the boat captain a better chance of spotting you before you drift too far out of visual range. If you're lost and wait until the surface to deploy an SMB, currents may have already pushed you a significant distance making it harder for the boat to visually locate you.


There is nothing stopping someone from putting an SMB on a reel and inflating it from depth, thereby making it or calling it a DSMB However in the event too much air is added at a significant depth you risk over-inflating the SMB and damaging it. I've seen plenty of SMBs inflated at depth without issues so this isn't always a concern, especially when inflating from a shallow depth. With an SMB on a reel, I only inflate partially at a depth of 10m/33fsw and let the expanding pressure do the work. Example: 33fsw is 2ATA, gas volume compresses 1/2. If inflate around half full at depth of 33fsw/10m, it should be full on surface


With that being said, A DSMB is a much better choice from inflating at depth because you'd have to worry about over expansion since they have a pressure relief valve or a way for excess air to vent