Changing hoses - require a reg adjustment?

[GFuterfas]

Hi,

If I want to occasionally switch my regs between 5' and 7' hoses, depending on the dive\training I'm doing, does it require that I have the regulator re-tuned somehow when I swap them out? Does this affect performance?

Thanks,
-Graham

 

[redacted]

Such a hose changet should not require any regulator adjustment. While there might be some theoretical effect caused by any hose change (diameter/length/friction) even the princess who found the pea would not sense that effect.

 

[Peter_C]

No adjustment needed, but I would recommend you find someone local to take you out for a skills dive and practice with your new hose. I would also recommend going straight for a 7' hose and skipping the 5' hose.

If you put up a post in the SoCal forum there are plenty of excellent divers that should be willing to mentor you.

 

[halocline]

I would also recommend going straight for a 7' hose and skipping the 5' hose.

I disagree. I have both and I use both frequently; 5' for OW diving with no canister light, and 7ft in overhead with the light. The only reason for the 7ft hose is to allow for single file air sharing through a restriction.

I know you can tuck the extra hose in your waist belt, but to me that is not nearly as comfortable or convenient as just routing the 5 ft hose across the chest.

Regarding the reg adjustment, there's a common misconception that a long hose might impede regulator performance because there's a longer distance for the air to travel. If anything it's the opposite; the longer hose provides a greater volume of air at IP, so when an equal demand is placed on it, the IP drop is actually theoretically less than with a short hose.

 

[Nemrod]

The initial IP drop with a longer hose would be less but the sustained flow IP drop would be greater compared to an equivalent ID shorter hose. However, in this case, there is no real difference worth fretting over.

N

 

[halocline]

The initial IP drop with a longer hose would be less but the sustained flow IP drop would be greater compared to an equivalent ID shorter hose.

N

I'm pretty sure this is not true. It's about volume of air at IP and what percentage of that volume is being drawn off by the 2nd stage, not a flow constriction. The flow rate through the 2nd stage is far lower than the flow capacity of the hose.

 

[GFuterfas]

Thanks, I feel comfortable doing the hose swap but didn't know if it affected anything.

Peter C, thanks, I requested to join the SoCal DIR forum on your advice and I'm just learning the local dive scene here. Definitely would like to find some local mentors. I'm torn on the 7' vs. 5' hose. My wife and I are going to Roatan in a few months and a 7' hose seems overkill. Obviously I need to practice with a 7' hose, but I don't have a can light and I'd like to be comfortable on vacation. I'm concerned the 7' hose might get in the way, but I figure I can have both and switch back and forth to see what I like.

Thanks to you all. I'm very interested in how the regulators work and you all seem to be quite knowledgable.

Best,
-Graham

 

[Peter_C]

I don't have a can light and I'd like to be comfortable on vacation. I'm concerned the 7' hose might get in the way, but I figure I

Then a five footer might be better suited to you, since you do not have a can light.

I started my long hose adventure with a 5' hose and quickly wound up with a can light and a 7' hose. Haven't used the 5' since, and believe I either sold it or more likely passed it onto someone else. My gal is in the process of becoming a certified diver, and using a 5' hose until she is comfortable enough in the water to add in her can light. Then a 7' will be added. If you don't mind throwing away the money you can go either way. You could also quickly make a fake can light to loop the hose under.

Either length do get with some of the friendly local long hosers and have them show you the ropes, and help set up your gear. You will need some bungee cord, and a hose around 24" long for your backup reg.

 

[fisheater]

A 7' routes very nicely for me, with or without a can light. Just tuck the bottom of the loop into your wasteband. No problem.

PLUS, it makes sharing very easy and allows you to dive single file while airsharing. Contrary to oft-repeated absolute statements, single file CAN BE necessary/highly desirable in OW situations, such as when diving in kelp beds or where there is a virtual overhead, such as boat traffic.

The 7' gives you options.