The Mariner goes out of San Pedro. So, San Pedro would be the closest option. However, if you don't mind about a 15-20 scenic taxi drive from Long Beach to San Pedro, I would suggest staying in Long Beach. Long Beach has more to do for entertainment, movies, restaurants, etc... and is more pretty in my opinion. Two good hotels to check out in Long Beach are the Hyatt, and the Queen Mary ship, which also functions as a hotel. They are at the Seaport Village area, with a free shuttle that takes you around. Be careful about where you stay in Long Beach, stick to the seaport village/port area. I actually grew up in the Long Beach area, it is my old stomping grounds. I have never stayed at a hotel in San Pedro, so I can't suggest a hotel there. This is just my opinion. Hope it helps.