Close to Kalapana on the Big Island of Hawaii, you can watch lava from the Pu’u O’o crater as it meets the ocean. It’s a 1-2 hour hike over rugged terrain from the Hawaii County viewing area before you reach these active pahoehoe lava flows. Due to the dangers of the hike, you should not attempt this without a guide unless you are experienced. For those who don’t fancy the hike, a lava boat tour is available – a 2.5 hour narrated coastline journey around the south-east side of the Big Island of Hawaii.
At the time of writing, there are actually no points of ocean entry, but this can change. See this page on the National Park Service website for the latest information.