Thanks for the responses so far. I know the rule of thumb shows 1/2" or bigger for a 38' boat. I was thinking along the lines of 3/8" myself being I am only tied up for short times in protected marinas and raft ups. I used 3/8" on my 29' Kryptonite and never had a problem. I used to have 4-15', 2-25, 1-50, and the anchor w/ line.
As far as fenders, I had 4-6" diameter fenders that were fine for the 29' but too small on my 38 so I just got 4 of the 8 1/2" ones.
I never go anywhere without my fenders and usually have a couple extra lines as well. In fact on the new boat I will probably have the small fenders tucked away....just in case.

good idea to have covers on the fenders to, many times its overlooked.

Tom,
I have 2-1/2 X 35'stoed in the Forward anchor locker
4-3/8" X 15 for each cleat 2 mid ship 2 stern
4- 8" fenders w/ 1/4"X 6' lines attached to pop in fender cleats.
200 feet of anchor line w/ 6' 3/8 chain attached
All my lines have my boat name embrodered on the eye. You can order them in Miami. I beleive they will be in the back tent.
See ya in Miami,

In our group we wont let someone raft up unless they have the soft bumper covers on them. One time had someone pull out a fender that had be under the back seat with sand and oil all over it and it tore my gel coat to pieces.
NO COVERS NO TIE UP!!!

I have a 30' boat and I carry a 35' line. In your case, you would need a 40'.
This will alow you to use 1 line while at a dock by looping around or behind a dock pole and still run the line from the bow to stern cleat. You can now tie off mid-ship with a short 8-10' spring line. This is clean, fast and works about 80% of the time.

We carry (4) 35' x 1/2" and (4) 25' x 1/2". We hade them made to order by Miami Cordage. They are true double-braided lines with spliced loops, not the sewn-together type. They will make the lines any length you want, with any size loop you want. Prices are competive with (proper, not el-cheapo) ready-made lines, too!

The loops and ends are whipped in different colors on the long vs. the short lines so we know what we are grabbing with a quick glance. If you use true double-braid, 3/8" will be strong enough, but "It won't look right". You may want to carry a pair of 15' x 3/8" rafting lines if you tie up to boats with small cleats, though....

Ive allways use the Samson lines.Ive found the 1/2 to big unless your in a storm, but the 3/8 still is rated to 3800lbs
http://www.samsonrope.com/index.cfm?...ope=103&inst=1

I bought this line to make up my fender lines,The 5/16 is rated to 8000lbs
http://www.samsonrope.com/index.cfm?...rope=95&inst=1




ck this out 6inch line
http://www.samsonrope.com/index.cfm?...rope=46&inst=1

four 40' 1/2" lines (mooring lines); two 20' 3/8" lines (spares); one 75' 5/8" line (towing); 250' 1/2" line + 10' chain (anchoring);
two 3/8" poly-propylene with rings (man overboard)