Lough Arrow is a limestone lake covering just over 3,100 acres, located primarily in County Sligo with an extension into County Roscommon. The lake averages 9 metres in depth and is sheltered on three sides by rolling hills. It is predominantly spring-fed with a relatively small catchment area, which contributes to clean, nutrient-balanced waters classified as mesotrophic — moderate in nutrient levels. At its northern end, the lake feeds the Unshin River, which flows northwest toward Ballisodare.

The lake supports kayaking, rowing, sailing, and stand-up paddleboarding alongside its well-established fishing tradition. Sligo Kayak Tours operates guided tours on the lake, with daily departures at 14:30, and no prior kayaking experience is required to join. A touring park near Riverstown provides camping with lake access, making it a practical base for multi-day trips.

There are four identified launch points around the lake. The first involves a steep, narrow lane and has parking for approximately two cars; it can accommodate trailer launches for those comfortable with the gradient, and smaller craft can be launched directly at the water's edge. The second is considered the best overall launch site, with a proper ramp, car access, and ample parking for trailer and small craft launches. The third has no ramp and requires carrying smaller craft approximately five metres to the water's edge, though parking is available. The fourth has a ramp with car access and parking, and also requires carrying smaller craft about five metres to the water's edge.

Irish law requires that anyone on lakes in a vessel under 7 metres in length wear a properly fitting, approved personal flotation device or lifejacket. Paddlers should be aware of this requirement before launching.

The lake is widely known as one of Ireland's premier wild brown trout fisheries, with the trout season running from 1 April to 30 September. During this period, fishing activity on the water will be more pronounced, which is worth factoring into route planning. The surrounding hills provide a visually distinctive backdrop, and the spring-fed, clean water quality adds to the appeal of paddling here.