10.—(1) Paragraphs (2) and (3) apply in cases where—
(a)heavy oil or bioblend which must not be used as fuel for propelling private pleasure craft (“fuel C”); and
(b)other heavy oil or bioblend (“fuel D”)
are mixed together by being taken into the fuel tank of a craft.
(2) When the craft is being used as a private pleasure craft the fuel in the mixture that is fuel D shall be treated as being used before the fuel in the mixture that is fuel C.
(3) When the craft is being used other than as a private pleasure craft the fuel in the mixture that is fuel C shall be treated as being used before the fuel in the mixture that is fuel D.