what size float line??

What length line you use when spearing/ab diving? I know it all depends on how deep your diving but would rather go to long then too short 

I like to have 10 to 15 feet longer than the depth of the water.

I have a 33' orange float line that I got from dolphin scuba in sac.never used it.I use just the standard yellow rope that any store that sells boating supplys. Very cheap cut to length.im currently using about 15' or so

A 50'er would be pulling on you if your diving 35'.  70' my recommendation.

I use a 35' when I dive. I only dive to around 20' feet or so.  when you first start diving with a float you will wrap it around everything. one you get use to it they are awesome.

I have a 33' orange float line that I got from dolphin scuba in sac.never used it.I use just the standard yellow rope that any store that sells boating supplys. Very cheap cut to length.im currently using about 15' or so

A quick shout out for safety:

I think rope is too dangerous to use as floatline.  I used it for a year before I discovered floatline.  Rope has a lot of memory and tends to coil under water.  It wrapped around my fins, legs, rocks, dive partners.  You could probably jump out of an airplane with 50 feet of rope, it's bound to snag on something.  If you are going to use rope you better have a knife that will cut it.

I have a 33' orange float line that I got from dolphin scuba in sac.never used it.I use just the standard yellow rope that any store that sells boating supplys. Very cheap cut to length.im currently using about 15' or so

A quick shout out for safety:

I think rope is too dangerous to use as floatline.  I used it for a year before I discovered floatline.  Rope has a lot of memory and tends to coil under water.  It wrapped around my fins, legs, rocks, dive partners.  You could probably jump out of an airplane with 50 feet of rope, it's bound to snag on something.  If you are going to use rope you better have a knife that will cut it.

+1 Rope won't allow you to slip through a tangle like float line will. I haven't dove deeper than 25 feet, and I use a 35 footer; hope to need a longer float line this season!!!

no experience with this line in the water...or me in the water here yet....new float line sitting here though

 I did get a very nice float line cut and pro ends/swivel snaps made to the size I wanted-in this case 50'-from Josh @ Neptonics in Santa Cruz...great price!!! and they have a tool and machine shop right there to cut/crimp ,make whatever they sell ...he also showed me a higher end float rope that later I may want to upgrade to......killer store ,if you have not been there-check it out... and I ended up with a real nice cheap cost float line .....

no experience with this line in the water...or me in the water here yet....new float line sitting here though

 I did get a very nice float line cut and pro ends/swivel snaps made to the size I wanted-in this case 50'-from Josh @ Neptonics in Santa Cruz...great price!!! and they have a tool and machine shop right there to cut/crimp ,make whatever they sell ...he also showed me a higher end float rope that later I may want to upgrade to......killer store ,if you have not been there-check it out... and I ended up with a real nice cheap cost float line .....

thats the same type of rope that I use except my is yellow

I have a 33' orange float line that I got from dolphin scuba in sac.never used it.I use just the standard yellow rope that any store that sells boating supplys. Very cheap cut to length.im currently using about 15' or so

A quick shout out for safety:

I think rope is too dangerous to use as floatline.  I used it for a year before I discovered floatline.  Rope has a lot of memory and tends to coil under water.  It wrapped around my fins, legs, rocks, dive partners.  You could probably jump out of an airplane with 50 feet of rope, it's bound to snag on something.  If you are going to use rope you better have a knife that will cut it.

+1 Rope won't allow you to slip through a tangle like float line will. I haven't dove deeper than 25 feet, and I use a 35 footer; hope to need a longer float line this season!!!

the type of rope I use floats.ive been using it for years haven't had any issues yet.i carry two knives with me at all times.if you freedive without a knife your really asking for it no matter what type of material your line is made off.

I use 50 and don't really dive for abs deeper than 15'.  I like this length for this depth, because I cover lots of ground while underwater and if I have to drop my iron for a marker, come up, 40' of the line may be underwater (kelp holding it down).  In bad vis, I can at least swim back to the end (on surface) then follow back. 

Side bar: Blue/yellow/white are the best colors to be visible down deeper.  Red/orange will turn neutral grey/black deeper.  Phenomenon is called 'attenuation'.

About 1.5 times your depth. I have a 65 foot that's good for me all around. PM IceColdChuck. He has float lines coming out of his ears.