Not a silly question, at all. And actually a matter of safe boating The extra line (and perhaps chain) protect the anchor from dislodging. As Rich notes above, the line and chain connecting the boat to the anchor can have a dramatic effect on how well the anchor holds. And often a bigger effect that just buying a heavier anchor. That isn't to say the anchor weight and shape are irrelevant. This is especially important in current or wind. On rivers with significant current, boaters often use lines that are 7 to ten times the depth of the water when setting anchor lines. Current and wind push the boat. With the line length fixed, current will force the bow will ride lower in the water. Too much current and too little anchor line and the boat can swamp from the bow in an instant. There is also the issue of accurate anchoring if you are concerned about positioning over structure. By moving past your target position, dropping anchor then releasing line you can drift or power back to the desired position. When I do this I also use a stern anchor, but that is another posting. Sorry for the long answer.