Both hard and soft woods are damaged, but the rate is faster in the soft woods or softer portions of a wood.
Timbers seriously attacked by marine borers are badly weakened or completely destroyed.

If the original strength of the material is to be preserved it is necessary to protect the wood from the borers.

This is sometimes accomplished by proper injection of creosote oil, and more or less successfully by the use of various kinds of external coatings.[38] No treatment, however, has proved entirely satisfactory.
[Footnote 38: See Smith, C.Stowell: Preservation of piling against marine wood borers.Cir.128, U.S.Forest Service, 1908, pp.

15.] FUNGOUS INJURIES[39] [Footnote 39: See Von Schrenck, H.: The decay of timber and methods of preventing it.Bul.14, U.S.Bu.

Plant Industry, Washington, D.C., 1902.