Jon Line

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Permalink Reply by kevrumbo on October 22, 2009 at 7:35pm

I use to simply pass the spooline around the downline/anchorline and pay out slack from the spool while holding onto the end with my other hand (see link ; the teammate in the picture is actually moving the loop to the next deco stop depth); and clip the double ender off on the line's tail & spool hole. That's still though a lot of abrading stress on a thin spooline in a strong current, and I'd rather use a dedicated jonline strap. Or better yet, if I'm on my X-Scooter, I just loop my nose clip leash around the downline/anchorline and stay clipped-on to the Scooter's towline . . .voila! --I'm hands free to do a deco gas switch.

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Permalink Reply by robert lucas on October 23, 2009 at 12:51pm

Nice Pic, Do you double line,for it looks pretty heavy?

Regards
BOB

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Permalink Reply by Maciej Arkuszewski on October 23, 2009 at 1:04pm

Hey Robert.

If you consider using jon line, your team should have a reasonable contingency for a case when it fails for one member. If the current is so strong that danger of someone drifting away and becoming separated is real, why not plan whole deco in drift to begin with? Obviously it involves a little more synchronization between teams and boat crew needs to be involved in planning.

Scooters are another option.

Regards

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Permalink Reply by robert lucas on October 23, 2009 at 2:16pm

Hey Macie, For deco dives we pull hook and drift, for hot drops one team member shoots bag. I was more interested for recreation dives.

Thanks
BOB

Maciej Arkuszewski said:

Hey Robert.

If you consider using jon line, your team should have a reasonable contingency for a case when it fails for one member. If the current is so strong that danger of someone drifting away and becoming separated is real, why not plan whole deco in drift to begin with? Obviously it involves a little more synchronization between teams and boat crew needs to be involved in planning.

Scooters are another option.

Regards

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Permalink Reply by robert lucas on October 23, 2009 at 2:25pm

No gill nets here, but big f%^^&& cargo boats, drifting commercial day fishing boats and pleasure boats that
seem to look for dive flags and lift bags:-)

Rainer said:

For most open ocean dives, whether or not you plan to use the anchor/up line, you need a contingency for drifting the deco (anchor/up line breaks, you have to ascend off the wreck without going back the anchor/up line, someone gets blown off the anchor/up line, etc). That said, I've done many dives where even though there is a drift deco contingency plan in effect, drifting the deco as opposed to ascending up the anchor/up line is just not desirable. These have been dives near busy shipping lanes and in areas known for free floating gill nets (i.e. most of the Northeast). While just not diving is always a possibility, for those who want to get in the water in such places, it's probably prudent to plan coming up the anchor line. If currents are strong enough, then a Jon line could very well come in handy. It just can't replace planning for what to do if you can't ascend the anchor line.


Maciej Arkuszewski said:

Hey Robert.

If you consider using jon line, your team should have a reasonable contingency for a case when it fails for one member. If the current is so strong that danger of someone drifting away and becoming separated is real, why not plan whole deco in drift to begin with? Obviously it involves a little more synchronization between teams and boat crew needs to be involved in planning.

Scooters are another option.

Regards

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Permalink Reply by kevrumbo on October 23, 2009 at 3:22pm

Along with commercial shipping lanes/boat traffic, thick fog is also a contraindication for drifting deco (i.e. what happened to Joe T and Delia some years ago). Find the anchorline/upline and stay with it! If you get lost or blown away by current, somebody in the team better have a surface deployed PLB (Personal Locater Beacon), and a handheld VHF radio (both can be stowed watertight inside an X-Scooter).

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Permalink Reply by kevrumbo on October 23, 2009 at 3:33pm

No . . .just loop it around the upline --don't wrap it or tie a girth hitch, it's too difficult to undo from the upline in stiff current. If you elect to drift off the upline for whatever reason, simply unclip from the spool hole and let go of that end. The spool line will just unloop and fall away from the anchorline/upline as you wind it up. . .

But it is better if you use a thicker, heavier line or a nylon strap for a dedicated jonline.

robert lucas said:

Nice Pic, Do you double line,for it looks pretty heavy?

Regards
BOB

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Permalink Reply by Richard on October 23, 2009 at 4:02pm

For a 5min ascent in a 1 knot current (a heck of alot) you aren't going very far. About 500ft downcurrent. While this may be too far/difficult to swim, the mother ship will almost assuredly have a chase boat. If they don't, I'd find another operator. If visibility is that bad (<1/10th mile), call it at the dock. Seriously, alot of these workarounds - while do-able - are giving you just enough confidence to get into real trouble.

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Permalink Reply by kevrumbo on October 23, 2009 at 4:23pm

Sometimes you can have a bright sunny morning here in SoCal at the dock or when you splash in, and then the fog rolls in with rapidly deteriorating surface visibilty later on in the afternoon --often while you're at depth. Also, you don't want to put your boat crew at risk dodging freighters and supertankers especially if they have to launch a little chase RIB in the shipping lanes of the Ports of Los Angeles and Long Beach (the nation's two largest commercial ports). In these instances, it's mandatory that you stay on the anchorline or upline . . .seriously you're asking for trouble if you elect to drift.
Richard said:

For a 5min ascent in a 1 knot current (a heck of alot) you aren't going very far. About 500ft downcurrent. While this may be too far/difficult to swim, the mother ship will almost assuredly have a chase boat. If they don't, I'd find another operator. If visibility is that bad (<1/10th mile), call it at the dock. Seriously, alot of these workarounds - while do-able - are giving you just enough confidence to get into real trouble.

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Permalink Reply by robert lucas on October 24, 2009 at 8:07am

On rec dives I carry a 1" nylon strap 6' long with a loop on one end and sucide clip on the other for wrecks that are hooked in. I read some DIR posts they recommend to just use a spool instead of a jon line, 1 less thing to carry. Anyway #24 cave line seems a little thin in a heavy current?

kevrumbo said:

No . . .just loop it around the upline --don't wrap it or tie a girth hitch, it's too difficult to undo from the upline in stiff current. If you elect to drift off the upline for whatever reason, simply unclip from the spool hole and let go of that end. The spool line will just unloop and fall away from the anchorline/upline as you wind it up. . .

But it is better if you use a thicker, heavier line or a nylon strap for a dedicated jonline.

robert lucas said:

Nice Pic, Do you double line,for it looks pretty heavy?

Regards
BOB

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Permalink Reply by robert lucas on October 24, 2009 at 8:20am

No chase boats in South FL. 50'/100' safety line with bouy tied to end on surface, then tied off to stern cieat. Same conditions hear with fog, but I don't thing as bad as you guys. The saying here is, if you don't like the weather, hang out another 5 min, thats how fast conditions can change.

Richard said:

For a 5min ascent in a 1 knot current (a heck of alot) you aren't going very far. About 500ft downcurrent. While this may be too far/difficult to swim, the mother ship will almost assuredly have a chase boat. If they don't, I'd find another operator. If visibility is that bad (<1/10th mile), call it at the dock. Seriously, alot of these workarounds - while do-able - are giving you just enough confidence to get into real trouble.

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Permalink Reply by Richard on October 24, 2009 at 12:21pm

Fellas, knock yourselves out, hang on the anchor line as much as you wish. The reality up here for deco dives its either impossible (even a jon line would be awful so you must drift) or its not necessary to actually attach yourself to the line (grab it off and on, or scooter up +drift back a bit). Certainly in a recreational situation you can just modify your stops to stagger along the upline, no big deal. While I haven't been diving "everywhere" the same principles do apply.

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