Looking for a great place to stay right on the beach in Hilton Head. Looking for ideas of vacation rentals on the coast.

There are a lot of rentals in HH, through the agencies and VRBO.

Marriott Monarch or Grand Ocean.
Sea Pines Beach and Tennis or Ocean Club.
Sea Pines Sea Crest is on the beach across from Coligny Plaza, not inside Sea Pines if you are into being in walking distance of shopping, restaurants and activity rather than sedate residential.

You are probably aware that March is perfect for tennis, biking, and hiking. Golf weather is nice, but much of the grass is still dormant. Swimming in the ocean is out of the question. Confirm you have a heated pool at your destination. You have some risk of cold weather.

Why Hilton Head?

Thanks for the feedback. I don't think we will be going to HH, too cold.

In March, I'd want to be at least as far south as Tampa for warm weather. Problem with that is dealing with the spring break crowd.