Another mooring question

Can anyone tell me which is better,

1. leaving the engine in the water when the boat is moored.

2. Tilting the engine up out of the water when the boat is moored.

Tilt it out. Otherwise you get plant and animal build up on it. Hinders the performance.

We alway tilt it. As said above the prob will be coated in plant life.

Always tilt engine up to prevent marine growth, If your engine has power tilt remember to engage the manual securing bracket to remove the weight from hydraulic ram.

Thanks for the replies lads.
That all makes sense to me.