Petrol tank. We have a 20 l tank on the platform behind the cockpit. As a reserve, we have a second 10 l tank stored in the cockpit locker. 20 l are for example needed to cross Kiel Canal (length approx. 100 km/54 sm, with our 8 HP two-stroke Yamaha, speed 4,5-5 kn).
Except Kiel Canal, this is possibly to much, as all of us know: with a DF 800 the motor is usually only needed to leave and enter the harbour

. On the other hand, on longer trips a full petrol tank is reassuring.
I have a kickboard in the cockpit locker. If we don't have a gas station directly at the harbour, we put both tanks on the kickboard. This way, we can refuel all 30 l very comfortable even if the gas station is kilometers away. Surprisingly, the tanks don't fall off the kickboard -- they fit perfectly.
Connection between outboard and rudder. We have that. Similar to the DF 920, it has a working angle of about +/- 45°. To maneuver in the harbour, +/- 90° are of course better -- it enables the DF 800 to turn around its own axis.
In other words, we dont't use use the connection in the harbour. I think it's helpful if we have to motor straight over a long distance (which is very seldom), especially with autopilot. The autopilot then steers both rudder and outboard. One can steer the boat with a fingertip - and it is a bit faster, approx. +0,1-0,2 kn. Pulling up the centerboard brings another +0,2 kn.
From my experience, a connection on the DF 800 is nice to have, but not necessary.
Niko
DF 800/279