the problem persists with 16M heap too:

$ csi -s ./arp-boats.scm -:g -:hm16M 2>&1 | grep --line-buffered resized | while read L ; do echo `date +%F_%T` "$L" ; done
2016-02-05_12:56:16 [GC] resized heap to 3145728 bytes
2016-02-05_12:56:16 [GC] resized heap to 6291456 bytes
2016-02-05_12:56:17 [GC] resized heap to 12583920 bytes
2016-02-05_12:56:22 [GC] resized heap to 16777216 bytes
2016-02-05_12:56:29 [GC] resized heap to 16777216 bytes
2016-02-05_12:56:29 [GC] resized heap to 16777216 bytes
2016-02-05_12:56:29 [GC] resized heap to 16777216 bytes
2016-02-05_12:56:29 [GC] resized heap to 16777216 bytes
... forever resizing