9.9 x 14 on my Hawk.  I don't have a tach, but at WOT I hit 35 mph.  I rarely run at WOT

 

The thing that should determine which way you go when you get to the point Nick was, is how are you planning to use the boat.
If you are planning to ski behind it or to regularly have a fully loaded boat, you should stay with the lower pitched prop as the higher pitched one will reduce your pulling power. If you are expecting to often run a lightly loaded boat and run at maximum speed you might want to go with the next higher pitch but you don't want to end up with the motor not able to reach at least the middle of the manufactures recommended operating RPM range.
If you expect to do both you might want to have both on hand and change back and forth. I keep two different pitch props in my boats and change as needed. And it is a good policy to always carry a spare prop anyway, there are monsters under those waves  
 

Not to beat a dying horse here, but what is the Prop consensus for a Vagabond/30Hp Tohatsu combo?

9.9x13 seems like a good option.  

Rocketman, if you are hitting the rev limit occasionally, would the 14 make sense?  or is the 13 a good compromise?

Thanks

 

My 30hp Tohatsu came with a 9.9" x 13 pitch prop which pushes my 1958 Vagabond to 30 mph. On rare occasion it will hit the rev limit of 6250 rpm.
Nick

Morning Mr. Magoo. My 30hp Tohatsu came with a 9.9” x 12 pitch prop which allowed the motor exceed max rpm’s at WOT.
I changed it to a 9.9” x 13 pitch prop which took care of the over revving situation. Running just under 30hp at around 6000rpm. On a 56/7 Vagabond.

Hello fellow Rivetheads.
I got good news this week my 30 hp Tohatsu has shipped. I know some of you are already running this motor. I need to know what pitch prop to start with. I know I need a tach for the final determination. I am putting the motor on a 1956 Vagabond. Thanks.