Never leave a diver behind

[DandyDon]

I don't think you understand how RFID works. The cards each person has does not have an energy source. Instead The radiowaves cause a voltage in the tag allowing it to send out a signal.

Under the boat could be an issue, though water I am pretty sure would block it. Near the boat would have a weak enough signal that the display would be yellow. At any time if the signal is not strong enough to be confident the board would be yellow.

Because the signal being sent out to active the tags are in specific locations they could be fine tuned to prevent people in the water being shown as in the boat.

As for cost a quick search came up this: Barcoding Inc. - FAQ - How much does an RFID tag cost?
$0.50 is not unreasonable. the expensive part would be the reader but that is a 1 time purchase if designed right and taken care of.

A few random thoughts.
RFID is used at least in my office as a key to enter and leave the building, we deal with very sensitive information. If it could randomly be giving a false positive I am sure we would be back to the good old fashion keypad in no time, or even biometrics.

This system would probably be similar to that which the cattle farmers use to inventory their heard. (gah another reason to call it a cattle boat!)
the ones without a battery are very durable. Mine has gone through the wash several times now.

Okay, I was looking at costs of tags with batteries - over $100 each. In small quantities, perhaps those could be saltwater proof and still cheap. How much is the Reader, tho? $4,000 per boat - and delicate to salt air?

I'd like a system that'd be affordable and acceptable to every 8-pack in Cozumel, Playa del Carmen, Holbox, Belize, etc. Sure, we have to start at home, but eventually...??

The problem I see with tokens is the "honey would you carry this for me" issue. Where the token of one diver ends up in the hands of another who just puts it on the station at the end of the dive.
Unlikely? yes but we are dealing with unlikely situations that crop up once in a blue moon and leaving this in the hands of the gues will get you into trouble.

Why didn't the DAN tag system work?

Hmmm... hmmm... just contemplating how to use tokens better. My experience with boats that use them is that they don't work that well because their use depends on the divers, mostly...
Howzabout this:
To get off the boat you must hand your token to the DM (or rolltaker). When you get back on, you get it back from the DM. The DM must be out of tokens for the boat to move.
Rick

See DAN tag question. No $4,000 reader to buy or maintain, it was free, but was not used.

 

[ekremer]

You would use tags w/o batteries (Passive RFID). This allows them to be low mantenance and cheap. The transponders have a max 1m range according to wikipedia I assume thats a radius from the transponder so ideally positioned thats 2 meters for each transponder. Which is of course a lot of hardware to cover a boat, but thats the most expensive part. Additionally the technology exists to extend this to 33 feet in 1 direction (as shown with the RFID passport hackers the passport tags were designed for only 4 cm and the "hackers" were apparently able to get 33 feet)


If we are only talking small boats like 8 packs I don't think a system like this would be necassary and the Dan Tag system would work 99% of the time IF its used. With RFID once its set up at the beginning of the trip its totally a no brainer glance at a screen and be done, only requirng real effort in case of an unexpected status.
If you are the owner and captain of your 8 pack or smaller I could see you may not want wanting this, but it would still make life a bit easier, and less error prone, which is the goal.

RFID would be a lot more usefull for cattleboats of 12 divers and up and almost the entire process once on the boat is automated.
Extra Tags could be kept on board and lost tags could be disabled and replacements issued to the diver so they can continue.

Purposful tampering with the tag would result in loss of diving privleges for the day. (if you really want to get lost at see not on the company watch)

Radio-frequency identification - Wikipedia, the free encyclopedia

 

[Jim Kerr]

And if the DM loses one?

Something like this will only work if there is a space where the token is suppose to be like on a board of some kind where you can physically see that there is a token missing. Like you are suggesting if it's a simple matter of token counting then it's the same as counting heads. If a token gets lost by diver or crew member, then it gets "recorded" as lost and the diver gets issued a "new" token and physically put into his/her hand. No one should be allowed to hand more than one token to the DM. i.e... "here's mine and my spouses" for that would be the same as answering for someone and defeat the purpose.

These procedures must be taken seriously and "strictly" enforced, no exceptions.

 

[DandyDon]

You would use tags w/o batteries.

Yeah, got that. I was heretofore looking at more expensive tags with batteries, but even without them - 4,000 readers.

 

[Jim Kerr]

You know an operation that lets you dive alone?

That's pretty common on Ca boats. They will not babtsit you and will treat you as the certified diver you are, it is all up to you. And there's no solo card required. Most if not all photographers dive solo.

 

[ekremer]

Dandy, im not 100% sure but I think all you need is 1 read for the boat and a bunch of satalite antenas that just report the signal back to the reader I think. That or my company has over $30,000 in door locks in this place. (All activity reports back to a central computer here the reader)

Here is a $60 RFID reader with a usb interface.
Phidgets Inc - PhidgetsRFID Reader Only (USB) #RFID-RDR-P1023

I don't think thats unresonable.

 

[bleeb]

Near the boat would have a weak enough signal that the display would be yellow. At any time if the signal is not strong enough to be confident the board would be yellow.

I guess I was imagining a typical six-pack sized boat, with the reader in the cockpit area with the other electronics and electrical supply. The person floating on the surface at the side of the boat might be closer to the receiver than the one climbing up the back. Maybe you could tune the antenna pattern to roughly match the shape of the boat, but could this be too limiting?

RFID is used at least in my office as a key to enter and leave the building, we deal with very sensitive information. If it could randomly be giving a false positive I am sure we would be back to the good old fashion keypad in no time, or even biometrics.

A half decent system should be pretty unlikely to generate false positives unless someone was deliberately setting out to spoof the reader. IIRC the 'higher end' systems (i.e. unlike retail where they're trying to keep the cost of tags below $0.05) are sending out actual digital codes, and each tag is unique. How unique depends on how many digits you want to pay for, but we're probably still talking <$1.

 

[ekremer]

With the short range of these readers, it would be easy to place them in the center of the boat and have the outer limits be the sides of the seating area.

 

[merxlin]

Most boats out here may have a few but on any given dive just use a single exit gate, and have a swim step for reboarding. Couldn't the system be configured for an in and out rather than just proximity? I.e. reads you out at the exit gate, reads you back in at the swimstep? No need for antennas all over making sure you are still on board.

 

[ekremer]

Except for those people who like to jump off and swim around during the SI, or using other parts of the boat to exit on (back roll?) It just increases risk and is no longer fool proof. Though at entry and exit you could give the divers a braclet like a hospital deal with a barcode and save some money. You also get into the he came on twice and never left issue.