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The English-Japanese Ocean dictionary mentions "bearing compass" here under "bearing" http://www.sainet.or.jp/‾k-naka/ejb.html
giving the translations as
houisokuteiyoukonpasu, houirashinngi, houikonpasu
Explanation: Depending upon the context, if the fact that that the compas is *hand-held* is important, then 携帯用方位コンパス is another option. If you want to make that sound more technical then 携帯用方位測定コンパス is yet another.