I have personnaly dived in a 40 sits tourism sub-marine in monaco , the sub hull was totaly made in a transparent resin (very thick), so i see no reason why a sub could not be made in a plastic material.---it is probably cast acrylic. As far as I know exists no clear resin.On the other hand i could note that this kind of building requires bigger means than the traditional stell hulls, it cant' be done in a small garage, requires big moults , amtmosphere control (humidity and temperature).Steel or GRP; I think the same workshop space is required. but you dont wake up the neighburs with the angle grinder.Personnaly i am really interrested in the result cause i would like to built an un motorized sub five meter long designed to welcome divers for 4 days with the possibility to reduce the pressure up to surface pressure at the end of stay.--Do you have a drawing?(post to moki) what hull diameter. It schould have some comfort for a long deco stay.or maybe am I a stupid newbie dreamer that has nothing to do here ??????--Noregards, Emile************************************************************************ ************************************************************************ ************************************************************************ The personal submersibles mailing list complies with the US Federal CAN-SPAM Act of 2003. Your email address appears in our database because either you, or someone you know, requested you receive messages from our organization. If you want to be removed from this mailing list simply click on the link below or send a blank email message to: removeme-personal_submersibles@psubs.org Removal of your email address from this mailing list occurs by an automated process and should be complete within five minutes of our server receiving your request. PSUBS.ORG PO Box 311 Weare, NH 03281 603-529-1100 ************************************************************************ ************************************************************************ ************************************************************************