diff --git a/src/p_user.c b/src/p_user.c
index a3af3cb78..a637ff4b2 100644
--- a/src/p_user.c
+++ b/src/p_user.c
@@ -5979,7 +5979,12 @@ static void P_3dMovement(player_t *player)
 	if (player->climbing)
 	{
 		if (cmd->forwardmove)
-			P_SetObjectMomZ(player->mo, FixedDiv(cmd->forwardmove*FRACUNIT, 15*FRACUNIT>>1), false);
+		{
+			if (player->mo->eflags & MFE_UNDERWATER)
+				P_SetObjectMomZ(player->mo, FixedDiv(cmd->forwardmove*FRACUNIT, 10*FRACUNIT), false);
+			else
+				P_SetObjectMomZ(player->mo, FixedDiv(cmd->forwardmove*FRACUNIT, 15*FRACUNIT>>1), false);
+		}
 	}
 	else if (!analogmove
 		&& cmd->forwardmove != 0 && !(player->pflags & PF_GLIDING || player->exiting
@@ -6013,7 +6018,12 @@ static void P_3dMovement(player_t *player)
 	}
 	// Sideways movement
 	if (player->climbing)
-		P_InstaThrust(player->mo, player->mo->angle-ANGLE_90, FixedDiv(cmd->sidemove*player->mo->scale, 15*FRACUNIT>>1));
+	{
+		if (player->mo->eflags & MFE_UNDERWATER)
+			P_InstaThrust(player->mo, player->mo->angle-ANGLE_90, FixedDiv(cmd->sidemove*player->mo->scale, 10*FRACUNIT));
+		else
+			P_InstaThrust(player->mo, player->mo->angle-ANGLE_90, FixedDiv(cmd->sidemove*player->mo->scale, 15*FRACUNIT>>1));
+	}
 	// Analog movement control
 	else if (analogmove)
 	{