v 1.7.1 released

Version 1.7.1 has been released. • Enemy ships now collide with each other (but do not damage each other). • Enemy escorts no longer hold fire when another enemy ship is in line of fire. • Fixed shimmy when sub is moving at 16x time-scale. • Convoy ship start positions staggered laterally. • Max convoy transport count increased to 9 (was 8). • Fixed bug where left rudder button would always be in "Toggle" mode. • Fixed bug where throttle UI would not match actual throttle setting. • Fixed bug where enemy escorts would sometimes pretend to be submarines. • Fixed bug where in-game options Volume would be 1/100 of actual volume value.