Before you enter the house on the shore, make a right and continue along the shore until you find a boulder at the very end.

Crouch jump (A + LB) and get on top of it, and you will be safe from all zombies

Note: Smokers and Hunters can still get you and the Boomer can still explode on you.

Also, a word of warning: the rock is slippery, so if there is more than one person on the rock, be careful.