Capt. JG wrote:
I'm considering adding a pyrometer to my boat.. the current temp gage is for
water, and I've heard from several sources that if there's a sudden
increase, it might not offer enough warning.

Something like this: http://www.livorsi.com/catalog/pyrometers.htm

However, I'm concerned about putting a hole in my exhaust manifold.

Anybody done this? Tips/tricks/things to watchout for?

If you don't want to putting a hole in the exhaust, you may wish to
consider an infrared thermometer. It is as accurate and measures the
temperature from the infra red radiation from the heating device, Exhaust.

--
Keith Nuttle
3110 Marquette Court
Indianapolis, IN 46268
317-802-0699