...accompanied by a "whalecaller." Now what exactly was the whalecaller? According to Molly it was a prototype designed by some Green Peace folks in an attempt to communicate with whales (this is a true story). It had a metal bowl which was filled with water and some metal struts of various lengths sprouting out from its top. One made the whale sounds by bowing the struts.....

this exactly describes an instrument i have heard called a waterphone

i think it was invented by a fellow named Richard Waters..see this
LINK