Re: Mounting a boat on trailer from water
You're going to get a lot of responses to this one!

And you may want to add some more details re: what kind of boat, type of trailer (roller or bunks) and what type of ramp.
I'm learning every time we go out (if you want some good chuckles just look at some of my recent posts), so take my advice with a grain of salt and listen closely to the veterans. Here are my tips:
- back the trailer in as reasonably close to the dock as you can, to allow the person on the dock to easily assist you in pulling the boat onto the trailer
- back the trailer in until the top of the trailer fenders are just barely submerged (this will vary by ramp/lake)
- I have my wife and/or son pull the boat around (usually it's on the "courtesy"/unused side of the dock) to the trailer and gently guide it towards the boat
- they throw me the bow line and I pull it towards our bunk trailer until I can't easily pull it anymore (the friction from the bunks stops it)
- I've already released the winch strap and walk the hook out towards the bow hook, hook it up and start winching it in
The best advice I can give someone is to practice at a slow time, or at a slow ramp. Practice makes perfect and helps reduce some of the self-induced stress you'll feel at a busier public ramp.
Again, I'm sure many other tips will follow!