Dive flag project (or size really does matter ;))

[NadMat]

Ok, I have not been very impressed with the options available commercially at any reasonable price point, so I decided to build my own dive flag buoy in what I considered an appropriate size to hope boaters will recognize it before they are on top of it.

To that end I bought a boat size nylon dive flag, a tent pole repair kit, several orange foam noodles, some pvc conduit and some assorted hardware. I still need to pick up a tank wrap and a strobe or two from the dive shop.

While shopping for pieces I also found a commercial unit that is somewhat like what I am building, if a little small, it at least was complete with carrying case and for 20 some odd bucks a good choice for a non-diy person as long as they weren't concerned with size. available at the local Academy...



but here it is next to my partially assembled project flag...



the foam noodles will be enclosed in a mesh tank wrap, and the buoy unit weighted at bottom to keep unit firmly upright. the flag and pole will be removable and collapsible in the manner of a standard fiberglass tent pole. there will be an eye bolt at the bottom to attach the line. I have an assortment of found anchors to choose from and plenty of cordage.

I can attach a tank light or two onto the mesh for better visibility on a night dive.

So what do y'all think? I am going out this weekend to play with weighting requirements, but the final assembly won't be till sometime next week.

What else might I do to make this better?

I think in this case, bigger really is better

[captndale]

Depending on the state in which you are diving, there may be minimum size requirements for the flag to be legal. That said, flags flown from boats should be proportional to the size of the boat. Flags that are intended to be towed by a diver are better seen if they are large and flown higher above the water. However, the larger the flag and float the more windage, drag and resistance to waves they have. It can be very fatiguing to tow a large flag/float through the water, especially in adverse weather conditions.

[NadMat]

Originally Posted by captndale

Depending on the state in which you are diving, there may be minimum size requirements for the flag to be legal. That said, flags flown from boats should be proportional to the size of the boat. Flags that are intended to be towed by a diver are better seen if they are large and flown higher above the water. However, the larger the flag and float the more windage, drag and resistance to waves they have. It can be very fatiguing to tow a large flag/float through the water, especially in adverse weather conditions.

state of texas states that in must be 15X15" at minimum on vessel or bouy, the academy unit is only 12X15", so does not in fact meet these requirements, and it is as big or bigger than the flags on most of the units I see in dive shops locally. The project unit is 20X23", and the flag is easily detachable from pole unit as is the pole unit from bouy so I can use the fiberglass pole unit on boat diving excursions. I could purchase other flag units if required, considering getting an alpha flag as well.

The buoy unit is intended more to be set in place to protect entry exit place, but could be towed, I would think as easily as a inner tube based flag buoy.

Texas law does not require you to even display dive flag, although I believe the corp of engineers lakes do. But if you do not display the dive flag you are not entitled to the protection it is supposed to afford. We usually just pop an smb if we have to surface away from buoy or protected shore area.

I found a great deal of useful information on dive flags at dive-flag.com

[NadMat]

Finally made it out to lake to run weighting tests and such.

After setting up on shore and letting Rocket play a bit...


I set up the weight on the buoy, starting with 12.5, and then adding another 2.5 for 15 total when 12.5 left it setting to high in water, here is pic of buoy with 15 lbs of weight.




Next stop was to add flag and pole to unit, to see if it was still stable with pole and flag attached. I also did quick tow test before adding pole and flag, towed real easy before flag. After adding pole and flag and checking to see that would stay firmly upright, I did second tow test, you could feel the difference, but still not that bad. Here is pic with flag in place.




next step is to find a good way to secure the permanent weight and a better fitting socket for the flag pole. I also need to install a stop to keep the outer ring of noodles from riding up. The weights I used for test, and will use for time being are some steel workout weights, they fit on center shaft of 3/4" conduit. for now I intend to install eyebolt in a end cap and secure end cap onto bottom of conduit using a bolt or pin through cap and conduit which will also hold weights on end of buoy. I will probably try to find next smaller size pvc to fit into current conduit and create tighter socket.

I also experimented with my mushroom anchor for securing it, and found that it not only secured it well, but it would float the anchor as well, although it did ride low in water when it was supporting anchor.

I need to pick up a rescue strobe or tank light to attach to buoy for night diving.

Any one else got any neat ideas before I get finished with my MKI divebuoy?

I want to have it ready for debut on 9/10 camp/dive trip this month, so clock is ticking...

[amaxey]

Retro reflective tape and radar reflectors. You could tie some old AOL CDs on there to flap in the breeze and draw attention, but that might bring more boats in to investigate than it would deter. Maybe a cow bell....nevermind...same problem as the CDs. Someone might steal your buoy if it's tricked out too much!

Okay, seriously. The good retro reflective tape can be seen for miles and even reflects during the day. A google search shows a bunch, but I would check with a marina and see if you can find the good stuff with the octogon pattern before you purchase online. Take a flashlight with you, even in daylight, from across the store you should get a strong reflection back. It reflects from several angles, but if you can put a foam ball halfway up the mast and run the tape around the ball then up and down on 4 sides, you would have a nice reflector from any sun/light angle. You could also put a band of the tape around the top of your noodles, if it would stick.

Al

[fire5man]

Now that you have worked out all the bugs can we see a photo of it out of the water. Great work. I spend many hours a day out on a boat and if I could share 1/2 of my stories that I have seen Non-diving just stupid boating you might be shocked.

Not much diving goes on where I work but if it did I am sure there would be lots of citations issued for violations of getting to close to a dive flag in the water.

I can see it already. Oh whats that

Anyways I would like to build something like you have there.

[drbill]

In my experience you could create a dive flag as large as the side of a barn and still have boaters and jet skiiers run right up to it with quizzical looks and ask the question "What does that mean?"

[In10se]

Well made Mat. Whats the tally on that unit so far anyway?

[marchand]

I would advise against putting a strobe on it for night diving because if anyone saw it at night they would have to investigate it by law.