The proper term is Bosun's Call, not pipe. You can get a copy of the various calls used aboard ship from the Admiralty Manual of Seamanship Vol 1 (British) If you cannot get the book from your library I would suggest you try some marine sites on internet. The General Call is very similar to the standard "Wolf Whistle" (used to attract a girls attention in the old days). A simple High to Low 2 second burst was "Carry on" and an 8 second High was to bring to Attention EG at Sunset or for Colours raising and lowering the Ensign.. Good Luck. Yours Aye! Dave