Okay, so you want to make a nice shot in low light, in a place that is infamously damaging to cameras. Here are my suggestions:
- Tripod ... check
- Remote shutter release, to avoid touching the camera too much ... check
- On the better tripods, it's possible to add a weight to the bottom of the center of the tripod. In many cases, your camera bag makes for a good weight, if it has more lenses in it. This prevents wind from interfering.
- Speaking of wind, the beach has sand! Standing next to the camera, out of the field of view, with a cardboard or foil car window shade expanded, will help you block wind and grit from flying into the camera while it's being used. This is also a great time to have an assistant to hold the car shade. You would not want foil (which can reflect bad light into the lens) if it were not low light.
Foils make for excellent light bounces, when doing modeling or studio styled work. Heck, they're even nice to carry around to give more light to flora and fauna when shooting outdoors on hikes.