O2 sensor and water

[Nils Björkman]

Hello

Im working on an EFI project. The purpose of this project is converting
and modifying an Volvo B230F engine to be used in a boat.

Now the turn has come to attach the O2 sensor. The following problems
occure:

1. If the O2-sensor gets in contact with water (in the exhaust
manifold), will it be destryoed, how does it work and so on.

2. How near the exhaust port can it be placed to be 300-800 DegC hot?
The exhaust manifold is water cooled and the outside of the cast iron
thing is not more than you can touch with your hand and not get burned.

Please let me know if anyone knows or thinks anything

Thanks

Nils Björkman
Sweden