diff --git a/internal/controller/fleet.go b/internal/controller/fleet.go
index 80a9af7..2d42935 100644
--- a/internal/controller/fleet.go
+++ b/internal/controller/fleet.go
@@ -81,7 +81,6 @@ func (c *Cache) FleetState(fleetID uuid.UUID) FleetState {
 	return *fs
 }
 
-// TODO: Hello! Wanna know fleet's speed? Good. Implement & test this func first.
 func (c *Cache) FleetSpeedAndMass(fi int) (float64, float64) {
 	c.validateFleetIndex(fi)
 	speed := math.MaxFloat64
diff --git a/internal/controller/fleet_test.go b/internal/controller/fleet_test.go
index 1420253..90450a0 100644
--- a/internal/controller/fleet_test.go
+++ b/internal/controller/fleet_test.go
@@ -1,6 +1,7 @@
 package controller_test
 
 import (
+	"math"
 	"slices"
 	"testing"
 
@@ -132,3 +133,45 @@ func TestJoinFleets(t *testing.T) {
 		g.JoinFleets(Race_0.Name, fleetOnPlanet2, fleetTargetTwo),
 		e.GenericErrorText(e.ErrShipsNotOnSamePlanet))
 }
+
+func TestFleetSpeedAndMass(t *testing.T) {
+	c, g := newCache()
+
+	c.MustPlanet(R0_Planet_0_num).Material = 100.
+	c.MustPlanet(R0_Planet_0_num).Capital = 100.
+	fleet := "Fleet"
+	var speed, mass float64
+
+	assert.NoError(t, c.CreateShips(Race_0_idx, Race_0_Gunship, R0_Planet_0_num, 3)) // 1
+
+	s := c.ShipGroup(0).Speed(c.MustShipClass(Race_0_idx, Race_0_Gunship))
+	m := c.ShipGroup(0).FullMass(c.MustShipClass(Race_0_idx, Race_0_Gunship))
+
+	assert.NoError(t, c.CreateShips(Race_0_idx, Race_0_Freighter, R0_Planet_0_num, 5)) // 2
+	assert.NoError(t, g.LoadCargo(Race_0.Name, 2, "MAT", 10., 0))
+
+	assert.NoError(t, c.CreateShips(Race_0_idx, Race_0_Freighter, R0_Planet_0_num, 7)) // 3
+	assert.NoError(t, g.LoadCargo(Race_0.Name, 3, "CAP", 10., 0))
+
+	assert.NoError(t, g.JoinShipGroupToFleet(Race_0.Name, fleet, 1, 0))
+	fleetIndex := 0
+	speed, mass = c.FleetSpeedAndMass(fleetIndex)
+	assert.Equal(t, s, speed)
+	assert.Equal(t, m, mass)
+
+	s = math.Min(s, c.ShipGroup(1).Speed(c.MustShipClass(Race_0_idx, Race_0_Freighter)))
+	m += c.ShipGroup(1).FullMass(c.MustShipClass(Race_0_idx, Race_0_Freighter))
+
+	assert.NoError(t, g.JoinShipGroupToFleet(Race_0.Name, fleet, 2, 0))
+	speed, mass = c.FleetSpeedAndMass(fleetIndex)
+	assert.Equal(t, s, speed)
+	assert.Equal(t, m, mass)
+
+	s = math.Min(s, c.ShipGroup(2).Speed(c.MustShipClass(Race_0_idx, Race_0_Freighter)))
+	m += c.ShipGroup(2).FullMass(c.MustShipClass(Race_0_idx, Race_0_Freighter))
+
+	assert.NoError(t, g.JoinShipGroupToFleet(Race_0.Name, fleet, 3, 0))
+	speed, mass = c.FleetSpeedAndMass(fleetIndex)
+	assert.Equal(t, s, speed)
+	assert.Equal(t, m, mass)
+}
diff --git a/internal/controller/ship_group.go b/internal/controller/ship_group.go
index f9aa18a..4ee4d36 100644
--- a/internal/controller/ship_group.go
+++ b/internal/controller/ship_group.go
@@ -304,7 +304,7 @@ func (c *Cache) LoadCargo(ri int, groupIndex uint, ct game.CargoType, ships uint
 		sgi = nsgi
 	}
 	capacity := c.ShipGroup(sgi).CargoCapacity(st)
-	freeShipGroupCargoLoad := capacity - c.ShipGroup(sgi).Load.F()
+	freeShipGroupCargoLoad := capacity - float64(c.ShipGroup(sgi).Load)
 	if freeShipGroupCargoLoad == 0 {
 		return e.NewCargoLoadNoSpaceLeftError()
 	}