Gunboats
The Gunboats are a secondary weapon for the Soldier which reduces blast damage from rocket jumps by 60%. The damage reduction is not applied to self-inflicted damage from rockets that injure enemies and do not provide the Soldier with reduced fall damage. When equipped by a roaming Soldier, the Gunboats allow him to transition quickly throughout the map.
Advantages & Disadvantages
Gunboats increase a soldiers mobility by allowing for more rocket jumps without heals and as a result reduce a Soldiers reliance on their Medic. As a result they are commonly used by the roaming Soldier in 6v6 or by Soldiers in Highlander that having a roaming play-style. They are rarely used by the Pocket in 6v6. It allows for a much more aggressive play-style as both soldiers can jump much more but reduces the Pockets ability to protect their medic in close range combat due to the loss of the Shotgun. This style was popularized by The Runaway 5 and the Tri Hards.
On rollout when running the Gunboats you take less damage thus making an Escape Plan rollout much harder. This leads to the Roamer generally jumping with the medic. The loss of the shotgun also reduces your firepower.