Frayed Lines

[wavster]

I have a general question about Flouro and Mono leaders:

Today I got hit twice under the 'cudas by something that ran with my live mac on
one line and sand dab on another (not at the same time).

Both lines were run deep.

It was a short fight with both hits, then the leader broke and was frayed at the break.
It didn't look like it popped at the hook. The leaders were 25lb P-line mono and were
freshly installed this morning.

The fact that it happened twice has me wondering. I don't think it was a sea lion,
though I could be wrong. It didn't have the trademark "all but head missing".

We could speculate all day on what hit them, but my question is about the leaders.
Should I use a heavier leader? What about no leader and straight spectra with a flexible rod tip?

Any other ideas or suggestions would be appreciated.