Although Velor does have seas in the traditional sense, these are few and shallow. Without icecaps, a large portion of the water on Velor exists as areas of truly enormous marshlands.
Blurring the distinction between sea and river, Velor's sea swamps are ubiquitous due to relatively uniform nature of Velor's surface. Except in a few singular cases, the difference between the planet's tallest elevation and deepest depth is no more than five miles above any other, which leads to geography that is relatively flat.
This, combined with the abundance of dense and/or heavy elements in Velor's crust prevent the easy creation of rivers and water has no choice but to spread out until it reaches a natural barrier, typically dozens or even hundreds of kilometres away.
Aside from an average depth of just three meters, the largest difference between a seaswamp and a sea is that the water's movement is more due to incline than lunar pull; seaswamps can only form when the vertical gradient between its source and estuary is between three and seven centimetres.
As a result the water in a seaswamp is always moving downhill, albeit slowly as even at peak velocity the body’s movement can only be measured in centimetres per hour and it can take well over five years for water to finally wash into its sea destination.
A consequence of both this and a seaswamp’s shallow depth is that the particulate count is always very high, resulting in water that is practically opaque and organisms often forgo eyes in favour of vibration sensitive whiskers or even sonar. Local Velorians will sometimes joke that the only way to tell the difference between mud and the swamp is that if you throw a stick in mud, it will still be there the next day.