I'm not much of a tranny skater but went to Washington Street once and it was as gnarly as it looks on video. It's right off of I-5 near the airport so it shouldn't be too hard to find. If you're trying to skate tranny and not look like a kook I'd recommend going to the Shockus skatepark (ocean beach). It's got tranny for days and a lot less sketchy than Washington st.
The new Linda Vista park is dope, it's best to go in morning during the week since kids are at school. On the weekend timing doesn't matter it's flooded with people especially bikes and scooters. Theirs a full pipe there a few bowls.
Less than a 10 minute drive from the airport you have memo park, Kimball park, and chicano park. All of them are dope except chicano's got cracks in the ground every so often. Kimball and memo are pretty much all street, chicano's a mix of both.
If you don't mind the drive, the alga Norte park in Carlsbad is decent for street/tranny. It's exit 44 off the 5.
I'm not a local, but have lived in San Diego for the past 5 years so if you need help finding parks feel free to hit me up.