Returns a list of NODC sea names

    source of list: http://www.nodc.noaa.gov/General/NODC-Archive/seanames.xml

def get_sea_names():
    '''
    Returns a list of NODC sea names

    source of list: http://www.nodc.noaa.gov/General/NODC-Archive/seanames.xml
    '''
    global _SEA_NAMES
    if _SEA_NAMES is None:
        resource_text = get_data("cc_plugin_ncei", "data/seanames.xml")
        parser = etree.XMLParser(remove_blank_text=True)
        root = etree.fromstring(resource_text, parser)
        buf = {}
        for seaname in root.findall('seaname'):
            name = seaname.find('seaname').text
            buf[name] = seaname.find('seacode').text if seaname.find('seacode') is not None else 'N/A'

        _SEA_NAMES = buf
    return _SEA_NAMES