Pat,
While I haven't done it with a 25, I have done it MANY times with my 22. Set-up is the key.
1) Prior to backing down the ramp, have both a bow and stern line attached. I used 25' lines and prepare them so a loop is hanging down over both the bow and the stern. It's important to have plent y of extra line.
2) Take the boat hook out of the boat and put it in the tow vehicle.
3) As you back down the ramp, you need to need to keep it fairly close to the dock (1-3') so you can easily reach the stern line with the boat hook. Get the stern well into the water. E.g. get to the normal point to launch ( with a roller trailer, the bow should still be just out of the water. Go back, grab the stern line with the boat hook and pull the stern line to the dock. With 25' you should have a lot left over. Leave the stern line in a pile on the dock.
4) Grab the bow line and release the boat from the winch. If you have 25' bow and stern lines, you should be able to launch the boat while holding the bow line and get to the stern line in plenty of time.
5) As the boat rolls off the trailer, walk with the bow line in hand back to the dock where the stern line is piled and grab it.
6) Once you have both lines in hand, things are under control.
7) Walk the boat to the far end of the dock and tie it off.
8) Return to the tow vehicle and park it.
You're set.
To retrieve,
1) Tie the boat at the end of the dock. Raise the engines.
2) Go get the trailer. Pull out plent of extra cable and prepare the winch for rewinding. If you have a truck, it's useful to lower the tailgate so you can use it to walk on.
3) Back the trailer into the water at the normal depth for loading. Again stay close to the dock.
4) Untie the boat and with a long bow line walk it forward to the trailer. Usually at Shilshole, I can hop onto my tailgate and pull the boat with the bow line onto the trailer.
5) Connect the latch to the bow eye and winch the boat foward. In a cross wind or cross current, it is useful to talk some nearby person into pushing/pull on the stern to get it into alignment. This can't always be done so sometimes you have to live with a less than perfect retrieve. It doesn't really hurt anything if the boat stern is no perfectly centered on the trailer.
However if the cross wind is too much, it may be necessary to drive the boat onto the trailer under power and to leave it in gear until the winch is tighten up. To do this, carefully drive the boat onto the trailer and get it up to the boaw rolloer. Apply a little power and steering to get the back end aligned. Leave it in gear, walk to the bow and attach the winch line to the bow eye. If you have it in gear with the wheel turned a bit, you can generally keep the stern lined up where you want it. Winch the boat up until it will not wander at the stern and turn the engines off and raise them. Tighten up on the winch line and then return to the tow vehicle to get off the ram. If the boat is close to the dock, this is simply a matter of walking back to the cockpit and hopping off. If not, you can often climb down from the bow to the tailgate of the tow vehicle and get out. On my trailer, I can go from the bow to the spare tire to the tailgate without getting my feet wet.
Hope this helps,
Roger on the SeaDNA