beachcolours(range, sealevel = 0, monochrome = FALSE,
             ncolours = if (monochrome) 16 else 64,
             nbeach = 1)
beachcolourmap(range, ...)range[1] and range[2].TRUE then a greyscale colour map is
    constructed.beachcolours.beachcolours, 
  a character vector of length ncolours specifying colour values.
  For beachcolourmap, a colour map (object of class "colourmap").Numerical values close to zero are portrayed in green (representing the waterline). Negative values are blue (representing water) and positive values are yellow to red (representing land). At least, these are the colours of land and sea in Western Australia. This colour scheme was proposed by Baddeley et al (2005).
  The function beachcolours returns these colours
  as a character vector, while beachcolourmap
  returns a colourmap object.
  The argument range should be a numeric vector of
  length 2 giving a range of numerical values.
  The argument sealevel specifies the height value that will
  be treated as zero, and mapped to the colour green.
  A vector of ncolours colours will be created,
  of which nbeach colours will be green.
  The argument monochrome is included
  for convenience when preparing publications.
  If monochrome=TRUE the colour map will be 
  a simple grey scale containing ncolours
  shades from black to white.
colourmap, 
  colourtools.