Out Board Engines

[Manoj Silva]

Hi,
I am making my self a small 18 feet boat to go out fishing.
The Sea Conditions here are rough compared to most countries.
The inital design I was told to do the trandsom height at 16 inches.
But recently somebody told me to change this to 21 inches and go for a long shaft engine. I was told a long shaft engine will provide more stability.
Is there any truth in this. Or should I proceed with my inital plans.
What do you guys have to say about this.
Also let me know what other improvements I need to make this more stable.
The boat need to have speed as well as must be able to take the pounding waves.

Manoj