Why prussiks and not simple tautline hitch?

[Rat]

Take a look at the #1855 variation shown in Wikipedia. That's my prefered method of tying a taut line in modern rope and I believe Rat's as well.

http://en.wikipedia.org/wiki/Taut-line_hitch

Yes, the #1855 variant is the correct way to tie the midshipman's hitch (commonly called the taught-line hitch).

The problem with this hitch is it has many names, and the names are used interchangeably.

Here are the basics:
If tying to a spar, use the Rolling hitch (commonly known) without the second turn tucked over the first.

If tying to rope use the taught-line hitch (commonly known) WITH the second turn tucked over the first. Do this and it will not slip.l The only material I have found it will not grip very well is large diameter Spectra sheathed rope, it slips when shock loaded.

Tie it like this in rope (guylines).
Grog's Rolling Hitch (taught-line hitch), the right way to tie it.

[Rat]

Additionally, if you have trouble with it slipping (and you are tying it correctly) add more turns above one another, don't add more half hitches above the turns. I use dynaglide, mason line, 550 cord and zing-it for my guylines and the standard midshipman's hitch variant does not slip on any of these.

[Bat]

I became an Eagle Scout in 1984 and have been a rock climber since 1994. I love knots and didn't know there were that many variations. Thanks again guys. Off to the garage to see the differences for myself firsthand.

Bat

[Rat]

I became an Eagle Scout in 1984 and have been a rock climber since 1994. I love knots and didn't know there were that many variations. Thanks again guys. Off to the garage to see the differences for myself firsthand.

Bat

You have no idea how many times I have heard that. Especially about the 'taught-line hitch'. An Eagle Scout friend showed me in the book how the taught-line was taught, and it was wrong in there (for what they were using it for anyway).

Anyway, glad I could spread some knot joy today!