2006 Launch 21 V packing size?

I'm looking for what size packing I need for this boat. It seems that 1/4 and 3/16 are the sizes available. I've been looking through the threads and haven't definitively found anything yet.

Just got the boat last fall, and found a "water fall" right by the packing nut a couple of weeks ago. I'm going to try tightening it, but want to have some packing material handy just in case, because the boat's an hour and a half away from home.

Thanks in advance for any help.

Great subject for a first post. I just sold a 2003 Outback and have been on their forum for the past 3 years.

Looks like I'm going to be hanging out around here now.