My
Pearson 35 had a galvanized cable installed in '06. Boat spent half its time in
SF Bay and the other half in
Hawaii. The cable was beginning to rust but still in pretty good shape when I changed it out for
Dyneema line in '12.
The
Dyneema line should be good indefinitely but there is one caution. The splice on the Dyneema line is quite long and won't pass through the turning block in the
bilge. Board hangs down a few inches as a result. Not a big thing but if you are anal about the board being all the way in the well, it could be an issue.
The cable on my
Morgan 35 was good for only a season and sometimes not that. For some unexplained reason, that particular boat suffered from severe
electrolysis on the center board cable. No problems with other underwater metal, however.