should be able to launch row boat with a ship deployed
uo.com
Rowboats copy their security settings from the ship owned by the placer of the rowboat, but only when the rowboat is placed on the same subserver as that ship. Otherwise, they get default security settings.
www.uoguide.com
It is the only other type of vessel deployable when you already have a boat or galleon deployed.
Ships Guide – Ultima Online
uo.com