When I was in submarines toilets could have been called hazardous.

On the older diesal electric boats inside each 'head' there were instruction on how to operate the flush. This consisted of opening and closing a series of valves in a particular order so that the with the lid down the contents of the loo could be flushed directly to sea.

Woe betide the poor sod who was new to boats and had not operated submarine heads before. Grinning matelots would gather nearby and listen to the valves being operated and wait to see if there was a dull thud, a back rush of air and a cry of 'Oh shit' as the contents blew back and decorated the happless flusher.

On nuclear boats there were was a very large tank which held the so called 'slop, drain and sewage'. These were regulary blown overboard prior to diving and when at periscope depth if operational circumstances allowed.

They were blown using a high pressure air blow into the tank forcing the contents through a one way valve to sea. Trouble was once the operation was complete you had a tank full of compressed air mixed with the any stuff left over from blowing. So the only recourse was to bleed the air back into the boat, and it always seemed to be at times when a meal was due to be served. An aerosol of human nature.

BTW the tanks had what were called **** mixers to make sure solids (i.e.paper were well broken down so they would not clog valves.

Once we were on the surface in a heavy beam sea proceeding to our diving area. The OOW on the fin asked permission to blow shit before rigging for diving. The captain said it was OK but was a change of direction required? The OOW blithley said no. The captain asked again, again the OOW said it was not needed. At this point the more experienced lookout quietly slid below the fin combing.

The OOW ordered the blow, at that point the boat rolled in a heavy swell causing the pooh tank vent hole which was normally below the waterline to be pointing upwards and windwards. A three inch high pressure bore of mixed pooh, pee and other nasties shot out to windward, the strong winds then did their work dispersing it backwards over the fin covering the OOW who only realised his error too late.

On coming below to clean up the skipper just calmly said to the rather maloderous officer that 'the weather was turning rather shitty'

There was no 'Groom of the Stool' for the captain either.