Buy a 50' hose (of your choice), then cut it at 15'/35' and add new ends. Now you've got a 15', 35', or 50', depending on need, without wresting more hose than you need at any given spot. The 15' is usually enough for most campgrounds that I've gone to, although the 35' has been needed a few times. Haven't needed the full 50' yet, but it's all there just in case.