Hi
just read through this thread as it contains info I may need, but just a few comments on the boat itself.
when you go ahead/astern on twin engines a boat tries to spin on the spot about a point between the two props.
when you are underway, steering using a rudder or tiller, the boat will turn on a point much further forward, the position of which is dictated by any keel and/or hull shape. The hull and keel shape will assist the turn and it will turn quicker and with less effort.
Additionally, props trying to spin a static boat will start to cavitate as the props are not moving through the water, but are trying to drag the water through themselves.
If you are going to use a servo on the tiller, why not just use one motor and use the second motor as a bow thruster? this would allow the boat to spin around its keel using the bow thruster, or turn when underway using the tiller.
Also, previous poster dead right, standard propulsion props are designed for max efficiency going ahead. your outboard brochure will show 2 completely different thrusts for ahead and astern. Look up a picture of a bowthruster prop and you will see it is completely different in design but will product equal thrust in both directions.
sooty
Sorry haven't looked at the video my media player doesn't work!