<html><head></head><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px"><div dir="ltr"><span>I am not sure but I did come across a cut away picture of one and it was filled with some sort of material. It really is amazing what the depth rating is for the cost.</span></div><div dir="ltr"><span>Hank</span></div> <br><div class="qtdSeparateBR"><br><br></div><div class="yahoo_quoted" style="display: block;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12px;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div dir="ltr"><font size="2" face="Arial"> On Tuesday, November 17, 2015 4:57 PM, Sean T. Stevenson via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<br></font></div> <br><br> <div class="y_msg_container">Are these floats hollow, or solid / blown closed-cell plastic?<br clear="none"><br clear="none">Sean<br clear="none"><br clear="none"><div class="yqt6239801975" id="yqtfd31597"><br clear="none">On 2015-11-17 16:48, hank pronk via Personal_Submersibles wrote:<br clear="none">> I am not sure I would want to risk an impact with the floats that could<br clear="none">> weaken them and potentially have them fail at depth. I feel it best to<br clear="none">> have them fully protected under a cowl. I suspect your right that they<br clear="none">> are tough enough, but I wouldn't want to chance it. I have seen a<br clear="none">> picture of a DW with about 20 floats tied to the front of the sub. They<br clear="none">> must have had an over weight item mounted temporarily that needed<br clear="none">> compensating. <br clear="none">> Hank<br clear="none">> <br clear="none">> <br clear="none">> <br clear="none">> On Tuesday, November 17, 2015 4:30 PM, Sean T. Stevenson via<br clear="none">> Personal_Submersibles <<a shape="rect" ymailto="mailto:personal_submersibles@psubs.org" href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br clear="none">> <br clear="none">> <br clear="none">> I only just now looked up the trawl floats. I notice that they have a<br clear="none">> depth rating which may match what you need, and you may also be able to<br clear="none">> take advantage of the form factor, instead of viewing it as a<br clear="none">> restriction... If the floats are available as spheres with a through<br clear="none">> hole, what about mounting an array of them down either side of your boat<br clear="none">> on a round bar which is part of the superstructure to serve double-duty<br clear="none">> as hard fenders? Placing them outboard like that would increase your<br clear="none">> surface stability as well.<br clear="none">> <br clear="none">> Sean<br clear="none">> <br clear="none">> <br clear="none">> On 2015-11-17 14:03, hank pronk via Personal_Submersibles wrote:<br clear="none">>> Sean,<br clear="none">>> I have looked at building steel buoyancy tanks- they are just to heavy<br clear="none">>> to be effective. I am trying to keep the sub as light as possible and<br clear="none">>> trawl floats are better than 50% buoyant to weight. Unless there is a<br clear="none">>> serious risk to using trawl floats, I think they are the most logical<br clear="none">>> and cost effective choice at 3 dollars per lb of buoyancy . I will<br clear="none">>> also have substantial MBT volume to offset failed trawl floats. If<br clear="none">>> I am wrong, please correct me, I would love to have steel tanks, that<br clear="none">>> is right up my alley.<br clear="none">>> Hank<br clear="none"><br clear="none">_______________________________________________<br clear="none">Personal_Submersibles mailing list<br clear="none"><a shape="rect" ymailto="mailto:Personal_Submersibles@psubs.org" href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br clear="none"><a shape="rect" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br clear="none"></div><br><br></div> </div> </div> </div></div></body></html>