Waste

Most effective way of managing waste is to reduce the amount of excess packaging you bring aboard.  In deep water well offshore organic wastecan be dumped.  Weighted cans and glass can be dumped as long as it sinks immediately.  We don't like doing it but it's heartbreaking to get to your destination only to dump it onshore and then see it dumped in the sea!  Places like Sudan and Eritrea will sort through your rubbish for goodies.  Uncrushed plastic bottles were on sale in sudanese markets!

Yoghurt

Warm 1 litre milk to 43^oC add 1 tblsp live yoghurt and leave in a warm place for 6-8 hours.  Reserve 1 tblsp yoghurt to make the next batch.