Yes. Most of the time. In Washington State, District and Municipal Courts require the Defendant's mandatory appearance at DUI or Physical Control Arraignment's.
Fortunately, Boating under the Influence (BUI) cases are not included. So if you have timely obtained counsel - your lawyer may file paperwork waiving that initial arraignment hearing and enter a plea of not guilty on your behalf. The Court Clerk will then set a pre-trial hearing as your next Court date. Typically 30-45 days from the original arraignment date. (Caveat: some local Court rules might still require your appearance - for example: Yakima County)
