Unfortunately the answer is no...the boat has to be ballasted down to the deck level more or less in order to get it to dynamically dive, the only way you can achieve the correct level of surface trim is either have it a surface runner only, or put in the static dive system.The Engle Piston tank a 750ml is not that expensive and neither is the BTS switch...Order or price them up from Engle modelbau in Germany NOT from over here.
www.Engel-Modelbau.de is the site they produce all sub kits and bits and it is the best quality in the world !!!You can ring them up and pay with credit card and the order usually gets to you in about 7-10 days the service is exceptional. The 750ml tank is 157 EUROS and the BTS2 is 57 EUROS. 214 Euros = £146 plus a little bit of postage. Hope this is of use