Why trawlers became early Royal Navy minesweepers

What were the first Royal Navy minesweepers before purpose-built classes?

They were largely converted trawlers whose towing skills suited sweeping gear; exposed mines could then be destroyed by gunfire.

The Royal Navy commissioned converted fishing trawlers before and during the First World War because their crews already understood towing heavy gear. Sweeps could catch mine moorings or bring the weapon to the surface where sailors tried to destroy it by gunfire. That hazardous procedure turned ordinary fishing knowledge into an immediate mine-countermeasure capability. The work was linked to a naval marksmanship badge and extra pay for sailors accurate enough to be assigned to a sweeper. The improvised wartime service developed its own incentives and specialist skills before purpose-built ships became common.