Diving Compass

[Lorenzoid]

Suunto doesn't make the compass ... it comes from a third party, in Italy I believe, and gets branded as a Suunto. Other compasses coming out of the same factory ... like the one you're looking at ... get made to the same specifications, with minor cosmetic changes and a different brand name.

How sad, considering that Suunto's very first product in the 1930s was a compass.

Anyway, that's good to know.

 

[MXGratefulDiver]

Not really, the world's changed a lot since 1930, and it's way more cost-effective for a lot of companies to spec out these products ... which makes them ultimately a lot more affordable for us.

... Bob (Grateful Diver)

 

[DaleC]

Another feature of the SK7 is a side viewing window that shows a reciprocal bearing. This is useful when swimming backwards on the surface.

 

[Keith.M]

Another feature of the SK7 is a side viewing window that shows a reciprocal bearing. This is useful when swimming backwards on the surface.

OK, this is the part of navigation that sometimes makes my head hurt.

How is it a reciprocol path?

If I set a heading for 300

When I look in the window, I am still on 300.

 

[DaleC]

In the water, with the compass held horizontally, point the compass as though you were swimming forward on a 120 bearing. Swimming backwards, looking in the side window, you will follow the 300 bearing.
Try it.

 

[T.C.]

OK, this is the part of navigation that sometimes makes my head hurt.
How is it a reciprocol path?
If I set a heading for 300
When I look in the window, I am still on 300.

It's because that window is for shooting a bearing. It's designed so that you can point the 'lubber' line (red line) at your destination, then, without moving the compass, look down and read the bearing to that destination. In this case, the target is bearing 300 deg. Turn the bezel until the lubber line points at 300 deg, then turn till the North arrow is under the raised double lines at zero deg.

To travel your reciprocal bearing, simply turn and line up the North arrow with the raised single line mark at 180 deg. No need to turn the bezel or anything else.

If you know this already; sorry; I'm not trying to insult your intelligence.

 

[Keith.M]

I understand. I will use this, thanks.

---------- Post added March 20th, 2014 at 09:51 PM ----------

It's because that window is for shooting a bearing. It's designed so that you can point the 'lubber' line (red line) at your destination, then, without moving the compass, look down and read the bearing to that destination. In this case, the target is bearing 300 deg. Turn the bezel until the lubber line points at 300 deg, then turn till the North arrow is under the raised double lines at zero deg.

To travel your reciprocal bearing, simply turn and line up the North arrow with the raised single line mark at 180 deg. No need to turn the bezel or anything else.

If you know this already; sorry; I'm not trying to insult your intelligence.

No problem T.C. I do understand setting a heading and using that and using my reciprocol path. I kind of missed about swimming backwards. That was why in my picture you could see I was getting both 300's in view. The double slots are in place, all good.

But I had not thought of using the compass, swimming backwards on my surface swim, with the reciprocol path in the window. I will use this, often.

 

[Ricky B]

Swimming backwards, looking in the side window, you will follow the 300 bearing.

I'm confused by "swimming backwards." Do you mean turning around and swimming back to where you came from?

 

[T.C.]

But I had not thought of using the compass, swimming backwards on my surface swim, with the reciprocol path in the window. I will use this, often.

I'd be careful about doing that. On the surface, you should see your destination (how else will you get a good bearing?), and it'd probably be easist to swim facing it. Underwater; you don't want to be swimming backwards for too long underwater. It's a great way to collide headfirst with that fire coral encrusted coral head....or that lionfish.

 

[MXGratefulDiver]

That feature isn't unique to Suunto ... most diving compasses have a side window, and it's not just for surface swimming, it's for reading the compass while you're swimming.

In the old days compasses often came mounted on a card that you held in both hands while using, looking down onto the top glass to read the compass. Most compasses today are designed to either be worn on the wrist or mounted to a console, where you hold the compass in front of you and sight down the lubber line like a gun sight. The side window accommodates this method of using the compass. I like Suunto's design, because they make the window large and easy to read ... but it's not "their" design, it's just how the compass is generally designed to be read. Not all diving compasses are designed this way, but I think the ones that are tend to be easier to use ...

... Bob (Grateful Diver)

---------- Post added March 21st, 2014 at 04:17 AM ----------

I'm confused by "swimming backwards." Do you mean turning around and swimming back to where you came from?

... he means swimming on the surface out to a point where you want to descend. Around where Dale and I both live (he's north of me by about 100 miles or so) we do mostly shore diving, and to get out to your descent point you turn over on your back and kick ... it's just easier to swim for long periods of time that way than it would be if you were face down on the surface. Sometimes you'll want to end your dive by ascending and surface swimming back to shore in much the same way. Since you can't see where you're going, you take a reverse compass heading and watch your compass on your return ...

... Bob (Grateful Diver)