Should we submerge a trailer when we launch a 18-ft boat from it? I
was asking this because I saw the boat dealer who sold my boat almost
fully submerged the trailer when they launched the boat for a sea
trail. I was under the impression that we should move the trailer down
to the point where the wheel axle is right above water. I was kind of
surprised to see that. Does this have something to do with the fact
that the trailer doesn't have a way to tilt the boat down? May be the
boat dealer just want the boat into the water as quickly as possible?

What's the proper way to launch a boat from a trailer if the trailer
doesn't have a way to tilt the boat?

Thanks in advance for any info.

Jay Chan