I do plan on staying in California hopefully, but I can't be sure of it. Even if I don't it wouldn't be a bad investment when the market is still low.
It is an excellent time to BUY a house, but will it be a good time (and financially worthwhile) to sell it in 3 years when the Navy decides they need you on the East coast? (No, don't plant on staying in one place forever in the Military). Do you think you can sell the house for a profit in 3-5 years? Is your CA market one where you can rent the house and still pay your mortgage if you had to? There are many people that didn't plan this correctly between 2005-2010 and lost 5 digits of money.
However, people that bought in 2002 and sold in 2004 (just before the fiasco) made out like BANDITS. Take a look at long-term real estate prices both national averages and in the area you're looking to buy. There are some places in the country that are doing miserably (e.g., Las Vegas) where others are booming. (Search on top 10 and worst 10 places to live in 2011).
Your desire to live in CA will be financially challenging. High real estate, high cost of living (San Diego is 2nd only to Hawaii). If you want to save money, San Diego is not a great place for a junior sailor to start off in real estate.
You're on the right track of "doing something" with your money. Keep doing research, it'll pay off.
Separately, you mentioned NFCU in your other thread. They are not always the best option for the sailor. In my experience in 2010, NFCU could not touch the low auto loan interest rate offered by BOA. Likewise with mortgage rates in 2008-2010. When it's time for things like auto and home loans...SHOP AROUND! NFCU and USAA seem to LOVE thanking a military veteran for their service...until you ask them to match the low loan rate. Then, it's "sorry".
If you're entering the military with $0.00 debt, then you're ahead of many, many people! (Good job!). Now, once the Nuclear Career starts throwing large sums of money at you, the trick is to resist the urge to buy a 2012 Corvette which will take 80% of your monthly pay. (Yes...seen that one too). Save 10% each payday and by all means....treat yourself to a new laptop when the time comes. You have to have fun too along the way!