Even with only 8 to 10 ft seas it can be too rough to tie alongside with short lines that could surge and stress uncontrollably when you change course. You are now also harnessed to a dangerous offshore situation if a large container ship’s swell were to hit you broadside.
With that type of tender and for a 3 mile ocean tow I would rig an oar as a tow post rigidly secured and wedged between the forward bench seat and gas tank shelf, (you tie a forestay to the bow…shrouds to forward tube handles).
It is a good idea to have tested this beforehand and carry a small bag of lashings specific for securing a tow post
This gives you a higher pivot point that will clear the operator and being forward of the outboard…. it will also allow the tender to pivot so as to steer properly with minor adjustments.
Use a long (floating) tow line to bow harness on sailboat and VHF
Tell sailboat to keep their rudder amidships unless asked otherwise, so as not to create any dangerous opposing sheer.
Slowly apply maximum 50% power and adjust length of tow for most comfortable ride.
Slow down, reduce tow length and turn boat into wind/current to stop momentum and clear towline when practical inside protected waters and depending on sea room and berth destination
I prefer then to simply secure the tender’s painter on the sailboat’s mid-ship cleat with generous scope
and use outboard’s astern propulsion
to give the sailboat slow headway.
Steerage is now done with the sailboat’s rudder and if it is a tight maneuver, best to do a practice figure 8 and stop before committing
In close quarters and steerage speed, the sailboat is now in a better position to pilot so they/you take over command on board the sailboat to guide tender assist and plan to stop just off the dock
with tender attached mid-ships on off dock