Single Diesel or Twin Outboard

Single Diesel
Pros

• Increased Cockpit Fish-ability
• COG shift forward slightly, better for running in rough seas
• Engine bulkhead already in place
• Tuna Door can be put on transom
• Emergency kicker needed (E-Tec Diesel Outboard)
  

Cons

• Longer Build time
• excessive amount of time calculating prop, shaft, and rudder locations and aligmnet
• keel and frames must be cut back to allow for shaft
• shaft would run through bottom connection point (potential weak point / leakage occuring)
• Helm must be designed for Engine Room Access
• Vessel will not be able to be in shallow water or run aground
• Gas Honda Generator will not run on Diesel for over night canyon trips

Twin Outboard
Pros

• Increased Safety and reliability, 2 Motors
• Better performance, adjustable propulsion line
• Quick installation  no excess build time
• Ease of engine maintenance
• Helm area arrangement not affected by engines
• Hull structure would remain unchanged 
• Gas generator able to tie into fuel supply

Cons

• Fish-ability limited at transom
• Tuna door has to be small or on side of hull
• Transom access form dock makes it hard to board vessel at some locations
• Double maintenance costs

While engine selection can still be either or,  both options have excellent reasons for using them. as for the inboard, shaft, prop and the transmission would pose a long shop time to calculate and build a surface which would be able to support the engine. At this point i am still planing on going with twin outboards. This can change in the future, but a definite decision is not required until the bottom shell plating is done.