Which Ice-Ducer do I need?

[SXViper]

I am looking at purchasing my first vex. Was wondering what ice-ducer I need. (90%-95% of my fishing will be in 15-30 feet of water fishing for walleye. Still hung up if I should spend the extra $100 on the fl18. I know I will if I end up purchasing one. Thanks for the help in advance.
Brian

[Guest]

This has not been mentioned as far as I know, so I'll bring it up:

If you will be ice fishing anywhere that there is ANY amount of current, you will want to have a puck style transducer mounted on a swivel arm. (the old style that came on the blue box)

Otherwise, you will never see your bait as the current drags it out of the self leveled cone angle.

Just thought I'd mention it to anyone that cares.....

PCG

[Guest]

Here are some cone angles and the approximate diameter that is covered.

10' deep
9° cone 1' 6.89"
12° cone 2' 1.23"
19° cone 3' 4.16"
20' deep
9° cone 3' 1.78"
12° cone 4' 2.45"
19° cone 6' 8.32"
30' deep
9° cone 4' 8.67"
12° cone 6' 3.68"
19° cone 10' 0.49"
40' deep
9° cone 6' 3.55"
12° cone 8' 4.90"
19° cone 13' 4.65"
50' deep
9° cone 7' 10.44"
12° cone 10' 6.13"
19° cone 16' 8.81"
60' deep
9° cone 9' 5.33"
12° cone 12' 7.35"
19° cone 20' 0.97"
70' deep
9° cone 11' 0.22"
12° cone 14' 8.58"
19° cone 23' 5.14"
80' deep
9° cone 12' 7.11"
12° cone 16' 9.80"
19° cone 26' 9.30"
90' deep
9° cone 14' 2.00"
12° cone 18' 11.03"
19° cone 30' 1.46"
100' deep
9° cone 15' 8.88"
12° cone 21' 0.25"
19° cone 33' 5.62"

[Scoot]

General rule of thumb for the 19 degree ducer is divide your depth by 3 and you get the diameter of your cone.
The question is, what's an appropriate cone diameter? The answer to this question will depend on depth. I'd also guess that there's a proportion-type answer rather than simply one number for what's best. I don't know what the answer is and I'd guess it'll depend upon personal preference too.
Any experts out there who can shed some light on this?
Scoot