Less then 2ft pir sensor

Hi.
I have a boat and a large bait board onthe back of it. I have put led lights all round the boat inside but its a pain with a light above the bait board.
I currently have a cigarette lighter port under the board which a cable runs to a small led light on a pole just above the board.
Im sick of having to turn on and off each time you do something on the board and get fish bits all over it.

I was thinking of a small waterproof per sensor on strapped to the light with only a 1ft -2ft proximity so when you walk near the board it turns on then turns off after 30secs of no detection.
The boat is 12v power setup.

Any ideas. Schematic it appreciated.

thanks
Stuart

i did just find this which would be ideal but how would i make the distance less than 1m?

**broken link removed**

I've got a couple of those.
Mine has a sensitivity pot, might not go down far enough for you though.
You might be able to reduce sensitivity by taping some of the window.

Yes, masking tape over the window works well to control direction and sensitivity. Easily adjusted.
If the window is removable you can also add a small mirror (ali foil on a bit of card) internally to control direction. I've done this with a PIR so that people, not small animals, trip the PIR.

hi,
PIR's can be purchased that come with a small kit of plastic 'bits' for fitting around the PIR window, so that the sensitivity and beam width can be reduced.
Also some have a sensitivity select that can be set on 'low' so as to ignore small targets like cats etc.