SMB spool length recommendations

[Dogbowl]

I just bought the Halcyon 6’ super slim SMB and Defender Pro spool in 100 feet (above left). According to some videos I watched on how to set up an SMB and spool, you’re supposed to cut off a significant length of the line from the spool to gain better access to the holes on the side of the spool. Makes total sense, but if I cut off 15 - 25 feet of line, I’ll end up with only 75 - 80 feet! Will that be sufficient length if I intend to deploy, say, between 50 and 30 feet of water while ascending to my safety stop, in warm tropical waters with some current such as Cozumel? Should I consider exchanging it for the 150 feet spool instead (above middle), although the spool itself will be larger, which is a con for travelling and carrying?

The videos on how to set up an SMB and spool:

 

[Zef]

Most of the spools that I have seen sold at shops here in Belgium come in either 30 or 50 meter varieties. That is between 98 and 164 feet of line. The size difference and weight difference of the spool, particularly the plastic kind, is nominal. The extra line is good to have for issues like deploying a DSMB from depth in a current, and also will allow you to discard a bit without ill effect so you can access the holes on the spool with your double-ender.

You should be able to arrange the spool and DSMB in such a way that it will fit in a pocket unless your pocket is really small. Getting stuff in and out of pockets, especially with gloves on, is kind of always a pain in the rump. Removing gear from and replacing it in a pocket is a skill that should be worked on in a pool and/or when diving outdoors just like mask clearing or any other diving related skill. Work out the kinks and keep working on the small stuff so that your skill set is perfect, or as close to it as possible, regardless of the conditions you are face with.

-Z

 

[tbone1004]

you need sufficient scope to deal with the current. In near 0 current, you don't need much of any scope at all. If there is high current, then the scope needs to be longer.
3:1 is considered standard, so the line should be 3x as long as you are deep when you plan to deploy.

150ft spool is the minimum that I would want for the depths that you are describing. Yes, that means you have a larger *typically only thicker* spool, but you need sufficient scope or you won't be able to stay at the depth you intend to stay at.

Yes you do need to remove line to make the holes accessible, no real way around that unfortunately

 

[Dogbowl]

Thanks for the posts.

@tbone1004 , does that make sense, to start deploying the SMB at between 50 and 30 feet, and ascending slowly to 15 feet safety stop?

 

[tomfcrist]

100ft is fine...150 is better if you are diving deeper than say 75-80ft.

3-1 is way too much scope to even think about assuming a drifting ascent. Some folks talk of tying off to a wreck and sending a SMB up from depth as an ascent line (if the hook pulls while you are down there), but I find this unrealistic. In any kind of real current the line will pop if you are hanging on to it.

Any thing deeper than 120’ I just use my primary reel instead. 400’ sidewinder.

 

[Lorenzoid]

It depends on the circumstances. In Cozumel, as you probably know, the DM deploys the SMB for the group. Cozumel dives are rarely square profiles; you typically get shallower later in the dive. So the DM typically deploys it late in the dive but before reaching safety stop depth--perhaps between 50 and 30 feet as you mention. Now, if you get separated from the group, which I suppose is the scenario you have in mind, you should deploy your own. This happened to me exactly once. However, the separation occurred late in the dive, so I simply ascended slowly to safety stop depth and deployed the SMB from there. I'm sure 50 feet of line would have been plenty. Obviously, how much scope you need also depends on the current. The 3:1 ratio that tbone mentioned may be the standard, but I think you'll rarely need that much line. If you want to prepare for all contingencies, then take 150 ft of line. I'd rather carry a more compact spool and take the risk that I might get separated earlier in the dive and/or encounter strong current. Keep in mind that, at least for Cozumel dives, you could probably surface and then deploy your SMB and still be picked up by the boat just fine--although it's a great skill to have, you don't NEED to deploy it from a significant depth, and rarely beyond safety stop depth. In addition to the small spool I bought for dives like Cozumel, I have a larger Light Monkey spool with 150 ft of line, and it is a bit unwieldy. I bought it for a cavern class and have been using it with an SMB lately because it's nicer than my el-cheapo brand small spool, but I think I will go back to the small spool for Cozumel-type diving.

 

[Dogbowl]

Yes! It’s a great skill to have and I want to learn how to do it with finesse, should I really need to do it one day.

 

[tomfcrist]

although it's a great skill to have, you don't NEED to deploy it from a significant depth, and rarely beyond safety stop depth.

Very true. The only time I can think of that you really need to send it up from significant depth is during deep deco. In any kind of serious current, you could be a mile or more from the boat prior to getting above 50’...and it’s nice to have a visual reference during blue water deco.

I’m aware that it probably doesn’t apply to the OPs diving, but just wanted to put it out there.

 

[RyanT]

I've got around 110' on my spool. It's a little tight to get the clip on the holes on the spool, but not a big deal. I shoot my bag from around 100ish feet. Even in current it works just fine as I'm largely drifting with my bag.

 

[tbone1004]

Thanks for the posts.

@tbone1004 , does that make sense, to start deploying the SMB at between 50 and 30 feet, and ascending slowly to 15 feet safety stop?

you're not doing deep deco, so I would not personally bother upgrading that spool, but I wouldn't deploy until I was at say 20ft. That's deeper than any boats that are going to be in that area, is a perfectly fine depth to make your stop, and doesn't require serious reeling during ascent. Anything that requires more than a 100ft spool with 75-80ft on it that is planned is done with a primary reel because it's easier to wind back for me.