The Floating Classroom has Petit Ponar samplers for shallow sediment samples, and spring-loaded Ekman Dredges for collecting samples at deeper locations (pictured).
On-board visual inspections of retrieved sediment samples can be messy! However, it is fascinating to see exactly what lies at the bottom of the lake. Sediments range from mud to rock, and often have a good deal of organic matter, mussels and other organisms immediately observable.
For middle school or high school biology classes, we recommend that teachers bring containers on-board so that samples can be returned to classrooms for further experimentation. One excellent activity is the Winogradsky Column, which allows students to observe and differentiate types of bacteria that are present in the sediment. The project takes several weeks to develop, but does not require any special equipment.
A brief video explanation is available here.