I'm going to Hilton Head, SC at the end of march. I'll be dock fishing. Any tips for reds and trout? Thanks.

Where are you staying?  That may help me recommend some more specific areas.

In general, target the mouths of creeks an hour before dead low tide.

3 hours ago, Chris at Tech said:

Where are you staying?  That may help me recommend some more specific areas.

In general, target the mouths of creeks an hour before dead low tide.

South beach, I'm fishing a little creek out of it

OK, that helps and I think I have a few suggestions...

1. I can neither confirm nor deny that there is a dock right adjacent to the walkway in Harbor Town which I know definitely holds trout in the fall, so I would assume it would hold in the spring as well.  Your issue will be being able to fish such a visible area without security asking you to move.
2. There are a few good sandbars right off the tip of South Beach, right where the river dumps into Calibogue sound
3. If you take the road heading from the plantation entrance back to Salty Dog, as you're getting close to SD you'll pass a pond on the left with a storm drain/culvert.  Fish that pond when tide is high, and when water is feeding into the pond from the storm drain.  I think it's called Sprunt Pond.
4. In the backwaters by Salty Dog, follow the creek around to the end. There's a riprap wall leading into another storm drain.  Same thing, fish when there's water movement through the pipe

Serious comment though, watch out for gators.  They are very very unlikely to give you any issues, but be aware that they're there, and just be aware when you're at water's edge -- especially when fighting, grabbing or releasing a fish