Aluminium anodes are often the preferred
choice for pipelines, oil rigs, jetties
and all sizes of hulls in sea water.
They weigh less and provide the same
protection for nearly a quarter as long
again. They also cost less than the
same shaped poured anode in zinc. Slightly
increased driving potential encourages their use
in brackish water, but magnesium should be
used in fresh water.
For an aluminium hull anodes are usually zinc
but with aluminium tabs or inserts see ZHC
Zincsmart Home page

Aluminum versions include the following:-
Mercury aluminium replacement anodes.
M76214A, M31640A, M43994A,
M55989A, M806105A, M806188A.
M806189A, M806190A, M821629A
M821630A Use these while under guarantee
also most Volvo anodes.

1" Collar anode
ZT1A pear with 8" (200mm) stud spacing
. . similar to 4.5lb pear but Wt 2.3lbs
ZC5A Weld-on . . Wt 1.8lbs
Z3WA Weld-on . . Wt 5lbs
Z3BA bar with 200mm mounting
as 9.5lb zinc bar. . Wt 3.75lbs
Z15A bar with 9" (225mm) mounting
. . as 15lb zinc bar, . . Wt 8lbs
Z19A Large weld-on bar
. . as 24lb zinc bar, Wt 10.5lbs
ZZDDA Divers-dream, Wt. 3.5lbs